Optical amplification apparatus

Claim 2

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and passing said separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means.

Claim 3

An optical amplification apparatus for amplifying inputting light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light: optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and passing said separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means.

Claim 4

An optical amplification apparatus for amplifying inputting light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light: optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and passing said separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means.

Claim 5

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light: optical amplifying means for amplifying said light at the one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass the split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said at least one path in accordance with control of said control means.

Claim 6

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light: optical amplifying means for amplifying said light at the one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass the split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said at least one path in accordance with control of said control means.

Claim 7

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light: optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass the split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said at least one path in accordance with control of said control means.

Claim 8

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light: optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass the split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said at least one path in accordance with control of said control means.

Claim 9

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light: optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein said optical power adjusting means includes: i) a rare earth added optical fiber amplifier including a first rare earth added optical fiber for passing said received light therethrough, a first excitation light source for outputting light for exciting said rare earth added optical fiber, and a first light combiner for said first excitation light source for introducing light outputted from said first excitation light source into said first rare earth added optical fiber; and ii) an adjusting light source for outputting light in the same wavelength band as light at at least one wavelength included in said received light, and a light combiner for said adjusting light source for introducing the light outputted from said light source into said rare earth added optical fiber amplifier in the direction opposite to a propagating direction of said received light.

Claim 10

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light: optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein said optical power adjusting means includes: i) a rare earth added optical fiber amplifier including a first rare earth added optical fiber for passing said received light therethrough, a first excitation light source for outputting light for exciting said rare earth added optical fiber, and a first light combiner for said first excitation light source for introducing light outputted from said first excitation light source into said first rare earth added optical fiber; and ii) an adjusting light source for outputting light in the same wavelength band as light at at least one wavelength included in said received light, and a light combiner for said adjusting light source for introducing the light outputted from said light source into said rare earth added optical fiber amplifier in the direction opposite to a propagating direction of said received light.

Claim 11

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein said optical power adjusting means includes: i) a rare earth added optical fiber amplifier including a first rare earth added optical fiber for passing said received light therethrough, a first excitation light source for outputting light for exciting said rare earth added optical fiber, and a first light combiner for said first excitation light source for introducing light outputted from said first excitation light source into said first rare earth added optical fiber; and ii) an adjusting light source for outputting light in the same wavelength band as light at at least one wavelength included in said received light, and a light combiner for said adjusting light source for introducing the light outputted from said light source into said rare earth added optical fiber amplifier in the direction opposite to a propagating direction of said received light.

Claim 12

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein said optical power adjusting means includes: i) a rare earth added optical fiber amplifier including a first rare earth added optical fiber for passing said received light therethrough, a first excitation light source for outputting light for exciting said rare earth added optical fiber, and a first light combiner for said first excitation light source for introducing light outputted from said first excitation light source into said first rare earth added optical fiber; and ii) an adjusting light source for outputting light in the same wavelength band as light at at least one wavelength included in said received light, and a light combiner for said adjusting light source for introducing the light outputted from said light source into said rare earth added optical fiber amplifier in the direction opposite to a propagating direction of said received light.

Claim 13

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein said control means includes: a storage unit for storing a plurality of parameters describing a combination of a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means; and a control unit for reading an arbitrary parameter from among said plurality of sets of parameters from said storage unit to control the gain or amplification performed by said optical amplifying an means and the gain of amplification or attenuation performed by said optical power adjusting means in accordance with the read parameter.

Claim 14

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein said control means includes: a storage unit for storing a plurality of parameters describing a combination of a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means; and a control unit for reading an arbitrary parameter from among said plurality of sets of parameters from said storage unit to control the gain or amplification performed by said optical amplifying an means and the gain of amplification or attenuation performed by said optical power adjusting means in accordance with the read parameter.

Claim 15

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein said control means includes: a storage unit for storing a plurality of parameters describing a combination of a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means; and a control unit for reading an arbitrary parameter from among said plurality of sets of parameters from said storage unit to control the gain of amplification performed by said optical amplifying means and the gain of amplification or attenuation performed by said optical power adjusting means in accordance with the read parameter.

Claim 16

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein said control means includes: a storage unit for storing a plurality of parameters describing a combination of a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means; and a control unit for reading an arbitrary parameter from among said plurality of sets of parameters from said storage unit to control the gain of amplification performed by said optical amplifying means and the gain of amplification or attenuation performed by said optical power adjusting means in accordance with the read parameter.

Claim 17

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively; and further comprising: monitoring means for detecting power of light at respective wavelengths multiplexer on said inputted light or on the light amplified by said optical amplification apparatus, wherein said control means controls a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means in accordance with the power of the light at the respective wavelengths detected by said monitor means.

Claim 18

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively; and further comprising: monitoring means for detecting power of light at respective wavelengths multiplexer on said inputted light or on the light amplified by said optical amplification apparatus, wherein said control means controls a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means in accordance with the power of the light at the respective wavelengths detected by said monitor means.

Claim 19

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively and further comprising: monitoring means for detecting power of light at respective wavelengths multiplexed on said inputted light or on the light amplified by said optical amplification apparatus, wherein said control means controls a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means in accordance with the power of the light at the respective wavelengths detected by said monitor means.

Claim 20

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively and further comprising: monitoring means for detecting power of light at respective wavelengths multiplexed on said inputted light or on the light amplified by said optical amplification apparatus, wherein said control means controls a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means in accordance with the power of the light at the respective wavelengths detected by said monitor means.

Claim 21

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, said light separator includes: a first optical coupler for splitting said received light; and optical filters arranged between said optical coupler and said plurality of paths corresponding to the light split by said optical coupler, each said optical filter for bidirectionally transmitting only light at a particular wavelength, said light combiner includes: an optical star coupler for combining the light at the respective wavelengths having propagated through said plurality of paths, said optical amplification apparatus comprises: means for splitting pan of light amplified by said optical amplifying means as monitor light; monitor light combining means for splitting said split monitor light by an optical star coupler and introducing said monitor light in the direction opposite to a propagating direction of the combined light including said light at the respective wavelengths; and a plurality of light detecting means for detecting power of the light at the respective wavelengths split by said optical coupler for splitting said monitor light which have transmitted said plurality of optical filters in the direction opposite to a direction of the light split by said optical coupler, and said control means controls a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, in accordance with the power of light at the respective wavelengths detected by said respective light detecting means.

Claim 22

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, said light separator includes: a first optical coupler for splitting said received light; and optical filters arranged between said optical coupler and said plurality of paths corresponding to the light split by said optical coupler, each said optical filter for bidirectionally transmitting only light at a particular wavelength, said light combiner includes: an optical star coupler for combining the light at the respective wavelengths having propagated through said plurality of paths, said optical amplification apparatus comprises: means for splitting pan of light amplified by said optical amplifying means as monitor light; monitor light combining means for splitting said split monitor light by an optical star coupler and introducing said monitor light in the direction opposite to a propagating direction of the combined light including said light at the respective wavelengths; and a plurality of light detecting means for detecting power of the light at the respective wavelengths split by said optical coupler for splitting said monitor light which have transmitted said plurality of optical filters in the direction opposite to a direction of the light split by said optical coupler, and said control means controls a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, in accordance with the power of light at the respective wavelengths detected by said respective light detecting means.

Claim 23

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, said light separator includes: a first optical coupler for splitting said received light; and optical filters arranged between said optical coupler and said plurality of paths corresponding to the light split by said optical coupler, each said optical filter for bidirectionally transmitting only light at a particular wavelength, said light combiner includes: an optical star coupler for combining the light at the respective wavelengths having propagated through said plurality of paths, said optical amplification apparatus comprises: means for splitting part of light amplified by said optical amplifying means as monitor light; monitor light combining means for splitting said split monitor light by an optical star coupler and introducing said monitor light in the direction opposite to a propagating direction of the combined light including said light at the respective wavelengths; and a plurality of light detecting means for detecting power of the light at the respective wavelengths split by said optical coupler for splitting said monitor light which have transmitted said plurality of optical filters in the direction opposite to a direction of the light split by said optical coupler, and said control means controls a gain of amplification or attenuation performed by optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, in accordance with the power of light at the respective wavelengths detected by said respective light detecting means.

Claim 24

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, said light separator includes: a first optical coupler for splitting said received light; and optical filters arranged between said optical coupler and said plurality of paths corresponding to the light split by said optical coupler, each said optical filter for bidirectionally transmitting only light at a particular wavelength, said light combiner includes: an optical star coupler for combining the light at the respective wavelengths having propagated through said plurality of paths, said optical amplification apparatus comprises: means for splitting part of light amplified by said optical amplifying means as monitor light; monitor light combining means for splitting said split monitor light by an optical star coupler and introducing said monitor light in the direction opposite to a propagating direction of the combined light including said light at the respective wavelengths; and a plurality of light detecting means for detecting power of the light at the respective wavelengths split by said optical coupler for splitting said monitor light which have transmitted said plurality of optical filters in the direction opposite to a direction of the light split by said optical coupler, and said control means controls a gain of amplification or attenuation performed by optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, in accordance with the power of light at the respective wavelengths detected by said respective light detecting means.

Claim 25

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, said optical amplification apparatus includes: means for splitting part of light amplified by said optical amplifying means as monitor light; monitor light combining means for introducing the split monitor light in the direction opposite to a propagating direction of the combined light including said light at the respective wavelengths; and a plurality of light detecting means for detecting power of the light at the respective wavelengths split by said optical coupler for splitting said monitor light which have transmitted in the direction opposite to a direction of the light combined by said optical coupler, and said control means controls a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, in accordance with the power of the light at the respective wavelengths detected by said plurality of light detecting means.

Claim 26

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, said optical amplification apparatus includes: means for splitting part of light amplified by said optical amplifying means as monitor light; monitor light combining means for introducing the split monitor light in the direction opposite to a propagating direction of the combined light including said light at the respective wavelengths; and a plurality of light detecting means for detecting power of the light at the respective wavelengths split by said optical coupler for splitting said monitor light which have transmitted in the direction opposite to a direction of the light combined by said optical coupler, and said control means controls a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, in accordance with the power of the light at the respective wavelengths detected by said plurality of light detecting means.

Claim 27

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, said optical amplification apparatus includes: means for splitting part of light amplified by said optical amplifying means as monitor light; monitor light combining means for introducing the split monitor light in the direction opposite to a propagating direction of the combined light including said light at the respective wavelengths; and a plurality of light detecting means for detecting power of the light at the respective wavelengths split by said optical coupler for splitting said monitor light which have transmitted in the direction opposite to a direction of the light combined by said optical coupler, and said control means controls a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, in accordance with the power of the light at the respective wavelengths detected by said plurality of light detecting means.

Claim 28

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, said optical amplification apparatus includes: means for splitting part of light amplified by said optical amplifying means as monitor light; monitor light combining means for introducing the split monitor light in the direction opposite to a propagating direction of the combined light including said light at the respective wavelengths; and a plurality of light detecting means for detecting power of the light at the respective wavelengths split by said optical coupler for splitting said monitor light which have transmitted in the direction opposite to a direction of the light combined by said optical coupler, and said control means controls a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, in accordance with the power of the light at the respective wavelengths detected by said plurality of light detecting means.

Claim 29

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, said optical separator includes: a first optical coupler for splitting said received light; and optical filters arranged corresponding to respective light split by said optical coupler, each said optical filter for bidirectionally transmitting only light at a particular wavelength, said light combiner includes: an optical star coupler for combining the light at the respective wavelengths each having propagated through each of said plurality of paths; said optical amplification apparatus comprises: means for splitting part of light amplified by said optical amplifying means as monitor light; monitor light combining means for splitting said split monitor light by an optical star coupler and introducing said monitor light in the direction opposite to a propagating direction of the combined light including said light at the respective wavelengths; and a plurality of light detecting means for detecting power of the light at the respective wavelengths split by said optical coupler for splitting said monitor light which have transmitted said plurality of optical filters in the direction opposite to a direction of the light split by said optical coupler, and said control means controls a gain of amplification or attenuation performed by optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, in accordance with the power of light at the respective wavelengths detected by said respective light detecting means, said control means including a comparator for comparing the power of the light at each of the respective wavelengths detected by said each light detecting means with a predetermined reference value, and means for controlling the gain of the amplification performed by said optical amplifying means in accordance with a maximum value of a difference with said reference value.

Claim 30

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, said optical separator includes: a first optical coupler for splitting said received light; and optical filters arranged corresponding to respective light split by said optical coupler, each said optical filter for bidirectionally transmitting only light at a particular wavelength, said light combiner includes: an optical star coupler for combining the light at the respective wavelengths each having propagated through each of said plurality of paths; said optical amplification apparatus comprises: means for splitting part of light amplified by said optical amplifying means as monitor light; monitor light combining means for splitting said split monitor light by an optical star coupler and introducing said monitor light in the direction opposite to a propagating direction of the combined light including said light at the respective wavelengths; and a plurality of light detecting means for detecting power of the light at the respective wavelengths split by said optical coupler for splitting said monitor light which have transmitted said plurality of optical filters in the direction opposite to a direction of the light split by said optical coupler, and said control means controls a gain of amplification or attenuation performed by optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, in accordance with the power of light at the respective wavelengths detected by said respective light detecting means, said control means including a comparator for comparing the power of the light at each of the respective wavelengths detected by said each light detecting means with a predetermined reference value, and means for controlling the gain of the amplification performed by said optical amplifying means in accordance with a maximum value of a difference with said reference value.

Claim 31

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, said optical separator includes: a first optical coupler for splitting said received light; and optical filters arranged corresponding to respective light split by said optical coupler, each said optical filter for bidirectionally transmitting only light at a particular wavelength, said light combiner includes an optical star coupler for combining the light at the respective wavelengths each having propagated through each of said plurality of paths; said optical amplification apparatus comprises: means for splitting part of light amplified by said optical amplifying means as monitor light; monitor light combining means for splitting said split monitor light by an optical star coupler and introducing said monitor light in the direction opposite to a propagating direction of the combined light including said light at the respective wavelengths; and a plurality of light detecting means for detecting power of the light at the respective wavelengths split by said optical coupler for splitting said monitor light which have transmitted said plurality of optical filters in the direction opposite to a direction of the light split by said optical coupler, and said control means controls a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, in accordance with the power of light at the respective wavelengths detected by said respective light detecting means, said control means including a comparator for comparing the power of the light at each of the respective wavelengths detected by said each light detecting means with a predetermined reference value, and means for controlling the gain of the amplification performed by said optical amplifying means in accordance with a maximum value of a difference with said reference value.

Claim 32

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, said optical separator includes: a first optical coupler for splitting said received light; and optical filters arranged corresponding to respective light split by said optical coupler, each said optical filter for bidirectionally transmitting only light at a particular wavelength, said light combiner includes an optical star coupler for combining the light at the respective wavelengths each having propagated through each of said plurality of paths; said optical amplification apparatus comprises: means for splitting part of light amplified by said optical amplifying means as monitor light; monitor light combining means for splitting said split monitor light by an optical star coupler and introducing said monitor light in the direction opposite to a propagating direction of the combined light including said light at the respective wavelengths; and a plurality of light detecting means for detecting power of the light at the respective wavelengths split by said optical coupler for splitting said monitor light which have transmitted said plurality of optical filters in the direction opposite to a direction of the light split by said optical coupler, and said control means controls a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, in accordance with the power of light at the respective wavelengths detected by said respective light detecting means, said control means including a comparator for comparing the power of the light at each of the respective wavelengths detected by said each light detecting means with a predetermined reference value, and means for controlling the gain of the amplification performed by said optical amplifying means in accordance with a maximum value of a difference with said reference value.

Claim 33

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said receive light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, said optical amplification apparatus includes: means for splitting part of light amplified by said optical amplifying means as monitor light; monitor light combining means for introducing the split monitor light in the direction opposite to a propagating direction of the combined light including said light at the respective wavelengths; and a plurality of light detecting means for detecting power of the light at the respective wavelengths split by said optical coupler for splitting said monitor light which have transmitted in the direction opposite to a direction of the light combined by said optical coupler, and said control means controls a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, in accordance with the power of the light at the respective wavelengths detected by said plurality of light detecting means, said control means including a comparator for comparing the power of the light at each of the respective wavelengths detected by said each light detecting means with a predetermined reference value, and means for controlling the gain of the amplification performed by said optical amplifying means in accordance with a maximum value of a difference with said reference value.

Claim 34

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said receive light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, said optical amplification apparatus includes: means for splitting part of light amplified by said optical amplifying means as monitor light; monitor light combining means for introducing the split monitor light in the direction opposite to a propagating direction of the combined light including said light at the respective wavelengths; and a plurality of light detecting means for detecting power of the light at the respective wavelengths split by said optical coupler for splitting said monitor light which have transmitted in the direction opposite to a direction of the light combined by said optical coupler, and said control means controls a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, in accordance with the power of the light at the respective wavelengths detected by said plurality of light detecting means, said control means including a comparator for comparing the power of the light at each of the respective wavelengths detected by said each light detecting means with a predetermined reference value, and means for controlling the gain of the amplification performed by said optical amplifying means in accordance with a maximum value of a difference with said reference value.

Claim 35

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, said optical amplification apparatus includes: means for splitting part of light amplified by said optical amplifying means as monitor light; monitor light combining means for introducing the split monitor light in the direction opposite to a propagating direction of the combined light including said light at the respective wavelengths; and a plurality of light detecting means for detecting power of the light at the respective wavelengths split by said optical coupler for splitting said monitor light which have transmitted in the direction opposite to a direction of the light combined by said optical coupler, and said control means controls a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, in accordance with the power of the light at the respective wavelengths detected by said plurality of light detecting means, said control means including a comparator for comparing the power of the light at each of the respective wavelengths detected by said each light detecting means with a predetermined reference value, and means for controlling the gain of the amplification performed by said optical amplifying means in accordance with a maximum value of a difference with said reference value.

Claim 36

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, said optical amplification apparatus includes: means for splitting part of light amplified by said optical amplifying means as monitor light; monitor light combining means for introducing the split monitor light in the direction opposite to a propagating direction of the combined light including said light at the respective wavelengths; and a plurality of light detecting means for detecting power of the light at the respective wavelengths split by said optical coupler for splitting said monitor light which have transmitted in the direction opposite to a direction of the light combined by said optical coupler, and said control means controls a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, in accordance with the power of the light at the respective wavelengths detected by said plurality of light detecting means, said control means including a comparator for comparing the power of the light at each of the respective wavelengths detected by said each light detecting means with a predetermined reference value, and means for controlling the gain of the amplification performed by said optical amplifying means in accordance with a maximum value of a difference with said reference value.

Claim 37

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said receiving light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, and said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths; a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing light outputted by said excitation light source into said first rare earth added optical fiber.

Claim 38

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said receiving light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, and said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths; a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing light outputted by said excitation light source into said first rare earth added optical fiber.

Claim 39

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, and said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths.

Claim 40

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, and said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths.

Claim 41

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths; a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing the light outputted by said excitation light source into said first rare earth added optical fiber.

Claim 42

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths; a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing the light outputted by said excitation light source into said first rare earth added optical fiber.

Claim 43

An optical amplification apparatus for amplifying inputted light having signal light of a plurality of different wavelength multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical amplifying means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths: a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing the light outputted by said excitation light source into said first rare earth added optical fiber.

Claim 44

An optical amplification apparatus for amplifying inputted light having signal light of a plurality of different wavelength multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical amplifying means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths: a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing the light outputted by said excitation light source into said first rare earth added optical fiber.

Claim 45

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light: optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, and said optical gain adjuster is an amplifier formed of semiconductor.

Claim 46

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light: optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, and said optical gain adjuster is an amplifier formed of semiconductor.

Claim 47

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, and said optical gain adjuster is an amplifier formed of semiconductor.

Claim 48

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, and said optical gain adjuster is an amplifier formed of semiconductor.

Claim 49

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical adjusting means and a gain of amplification performed by said optical amplifying means respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and said optical gain adjuster is an amplifier formed of semiconductor.

Claim 50

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical adjusting means and a gain of amplification performed by said optical amplifying means respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and said optical gain adjuster is an amplifier formed of semiconductor.

Claim 51

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and said optical gain adjuster is an amplifier formed of semiconductor.

Claim 52

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and said optical gain adjuster is an amplifier formed of semiconductor.

Claim 53

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, and said optical amplifying means is an amplifier formed of semiconductor, said amplifier formed of semiconductor having the same composition as the semiconductor forming said optical gain adjuster.

Claim 54

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, and said optical amplifying means is an amplifier formed of semiconductor, said amplifier formed of semiconductor having the same composition as the semiconductor forming said optical gain adjuster.

Claim 55

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelenghts different from the wavelength of said; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, and said optical gain adjuster is an amplifier formed of semiconductor, said amplifier formed of semiconductor having the same composition as the semiconductor forming said optical amplifying means.

Claim 56

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelenghts different from the wavelength of said; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, and said optical gain adjuster is an amplifier formed of semiconductor, said amplifier formed of semiconductor having the same composition as the semiconductor forming said optical amplifying means.

Claim 57

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light: optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and said optical gain adjuster is an amplifier formed of semiconductor, said amplifier formed of semiconductor having the same composition as the semiconductor forming said optical amplifying means.

Claim 58

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light: optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and said optical gain adjuster is an amplifier formed of semiconductor, said amplifier formed of semiconductor having the same composition as the semiconductor forming said optical amplifying means.

Claim 59

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and said optical gain adjuster is an amplifier formed of semiconductor, said amplifier formed of semiconductor having the same composition as the semiconductor forming said optical amplifying means.

Claim 60

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and said optical gain adjuster is an amplifier formed of semiconductor, said amplifier formed of semiconductor having the same composition as the semiconductor forming said optical amplifying means.

Claim 61

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light: optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, and said optical amplifying means includes: a second rare earth added optical fiber; a second excitation light source for outputting light for exciting said second rare earth added optical fiber; and a light combiner for said second excitation light source for introducing the light outputted from said second excitation light source into said second rare earth added optical fiber.

Claim 62

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light: optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, and said optical amplifying means includes: a second rare earth added optical fiber; a second excitation light source for outputting light for exciting said second rare earth added optical fiber; and a light combiner for said second excitation light source for introducing the light outputted from said second excitation light source into said second rare earth added optical fiber.

Claim 63

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, and said optical amplifying means includes: a second rare earth added optical fiber; a second excitation light source for outputting light for exciting said second rare earth added optical fiber; and a light combiner for said second excitation light source for introducing the light outputted from said second excitation light source into said second rare earth added optical fiber.

Claim 64

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, and said optical amplifying means includes: a second rare earth added optical fiber; a second excitation light source for outputting light for exciting said second rare earth added optical fiber; and a light combiner for said second excitation light source for introducing the light outputted from said second excitation light source into said second rare earth added optical fiber.

Claim 65

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light: optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and said optical amplifying means includes: a second rare earth added optical fiber; a second excitation light source for outputting light for exciting said second rare earth added optical fiber; and a light combiner for said second excitation light source for introducing the light outputted from said second excitation light source into said second rare earth added optical fiber.

Claim 66

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light: optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and said optical amplifying means includes: a second rare earth added optical fiber; a second excitation light source for outputting light for exciting said second rare earth added optical fiber; and a light combiner for said second excitation light source for introducing the light outputted from said second excitation light source into said second rare earth added optical fiber.

Claim 67

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuation light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and said optical amplifying means includes: a second rare earth added optical fiber; a second excitation light source for outputting light for exciting said second rare earth added optical fiber; and a light combiner for said second excitation light source for introducing the light outputted from said second excitation light source into said second rare earth added optical fiber.

Claim 68

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuation light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and said optical amplifying means includes: a second rare earth added optical fiber; a second excitation light source for outputting light for exciting said second rare earth added optical fiber; and a light combiner for said second excitation light source for introducing the light outputted from said second excitation light source into said second rare earth added optical fiber.

Claim 69

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising, optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: i) a rare earth added optical fiber amplifier including a first rare earth added optical fiber for passing said received light therethrough, a first excitation light source for outputting light for exciting said rare earth added optical fiber, and a first light combiner for said first excitation light source for introducing light outputted from said first excitation light source into said first rare earth added optical fiber; and ii) an adjusting light source for outputting light in the same wavelength band as light at at least one wavelength included in said received light, and a light combiner for said adjusting light source for introducing the light outputted from said light source into said rare earth added optical fiber amplifier in the direction opposite to a propagating direction of said received light, and said optical amplifying means includes: a second rare earth added optical fiber having the same composition as said first rare earth added optical fiber; a second excitation light source for outputting light for exciting said second rare earth added optical fiber; and a light combiner for said second excitation light source for introducing the light outputted by said second excitation light source into said second rare earth added optical fiber.

Claim 70

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising, optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: i) a rare earth added optical fiber amplifier including a first rare earth added optical fiber for passing said received light therethrough, a first excitation light source for outputting light for exciting said rare earth added optical fiber, and a first light combiner for said first excitation light source for introducing light outputted from said first excitation light source into said first rare earth added optical fiber; and ii) an adjusting light source for outputting light in the same wavelength band as light at at least one wavelength included in said received light, and a light combiner for said adjusting light source for introducing the light outputted from said light source into said rare earth added optical fiber amplifier in the direction opposite to a propagating direction of said received light, and said optical amplifying means includes: a second rare earth added optical fiber having the same composition as said first rare earth added optical fiber; a second excitation light source for outputting light for exciting said second rare earth added optical fiber; and a light combiner for said second excitation light source for introducing the light outputted by said second excitation light source into said second rare earth added optical fiber.

Claim 71

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelength multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: i) a rare earth added optical fiber amplifier including a first rare earth added optical fiber for passing said received light therethrough, a first excitation light source for outputting light for exciting said rare earth added optical fiber, and a first light combiner for said first excitation light source for introducing light outputted from said first excitation light source into said first rare earth added optical fiber; and ii) an adjusting light source for outputting light in the same wavelength band as light at at least one wavelength included in said received light, and a light combiner for said adjusting light source for introducing the light outputted from said light source into said rare earth added optical fiber amplifier in the direction opposite to a propagating direction of said received light, and said optical amplifying means includes: a second rare earth added optical fiber having the same composition as said first rare earth added optical fiber; a second excitation light source for outputting light for exciting said second rare earth added optical fiber; and a light combiner for said second excitation light source for introducing the light outputted by said second excitation light source into said second rare earth added optical fiber.

Claim 72

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelength multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: i) a rare earth added optical fiber amplifier including a first rare earth added optical fiber for passing said received light therethrough, a first excitation light source for outputting light for exciting said rare earth added optical fiber, and a first light combiner for said first excitation light source for introducing light outputted from said first excitation light source into said first rare earth added optical fiber; and ii) an adjusting light source for outputting light in the same wavelength band as light at at least one wavelength included in said received light, and a light combiner for said adjusting light source for introducing the light outputted from said light source into said rare earth added optical fiber amplifier in the direction opposite to a propagating direction of said received light, and said optical amplifying means includes: a second rare earth added optical fiber having the same composition as said first rare earth added optical fiber; a second excitation light source for outputting light for exciting said second rare earth added optical fiber; and a light combiner for said second excitation light source for introducing the light outputted by said second excitation light source into said second rare earth added optical fiber.

Claim 73

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light: optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths; a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing the light outputted by said excitation light source into said first rare earth added optical fiber and said optical amplifying means includes: a second rare earth added optical fiber having the same composition as said first rare earth added optical fiber; a second excitation light source for outputting light for exciting said second rare earth added optical fiber; and a light combiner for said second excitation light source for introducing the light outputted by said second excitation light source into said second rare earth added optical fiber.

Claim 74

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light: optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths; a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing the light outputted by said excitation light source into said first rare earth added optical fiber and said optical amplifying means includes: a second rare earth added optical fiber having the same composition as said first rare earth added optical fiber; a second excitation light source for outputting light for exciting said second rare earth added optical fiber; and a light combiner for said second excitation light source for introducing the light outputted by said second excitation light source into said second rare earth added optical fiber.

Claim 75

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths; a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing the light outputted by said excitation light source into said first rare earth added optical fiber, and said optical amplifying means includes: a second rare earth added optical fiber having the same composition as said first rare earth added optical fiber; a second excitation light source for outputting light for exciting said second rare earth added optical fiber; and a light combiner for said second excitation light source for introducing the light outputted by said second excitation light source into said second rare earth added optical fiber.

Claim 76

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths; a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing the light outputted by said excitation light source into said first rare earth added optical fiber, and said optical amplifying means includes: a second rare earth added optical fiber having the same composition as said first rare earth added optical fiber; a second excitation light source for outputting light for exciting said second rare earth added optical fiber; and a light combiner for said second excitation light source for introducing the light outputted by said second excitation light source into said second rare earth added optical fiber.

Claim 77

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light: optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths; a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing the light outputted by said excitation light source into said first rare earth added optical fiber, and said optical amplifying means includes: a second rare earth added optical fiber having the same composition as said first rare earth added optical fiber; a second excitation light source for outputting light for exciting said second rare earth added optical fiber; and a light combiner for said second excitation light source for introducing the light outputted by said second excitation light source into said second rare earth added optical fiber.

Claim 78

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light: optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths; a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing the light outputted by said excitation light source into said first rare earth added optical fiber, and said optical amplifying means includes: a second rare earth added optical fiber having the same composition as said first rare earth added optical fiber; a second excitation light source for outputting light for exciting said second rare earth added optical fiber; and a light combiner for said second excitation light source for introducing the light outputted by said second excitation light source into said second rare earth added optical fiber.

Claim 79

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light: optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths; a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing the light outputted by said excitation light source into said first rare earth added optical fiber, and said optical amplifying means includes: a second rare earth added optical fiber having the same composition as said first rare earth added optical fiber; a second excitation light source for outputting light for exciting said second rare earth added optical fiber; and a light combiner for said second excitation light source for introducing the light outputted by said second excitation light source into said second rare earth added optical fiber.

Claim 80

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light: optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths; a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing the light outputted by said excitation light source into said first rare earth added optical fiber, and said optical amplifying means includes: a second rare earth added optical fiber having the same composition as said first rare earth added optical fiber; a second excitation light source for outputting light for exciting said second rare earth added optical fiber; and a light combiner for said second excitation light source for introducing the light outputted by said second excitation light source into said second rare earth added optical fiber.

Claim 81

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light: optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and a wavelength of light outputted by said first excitation light source ranges from 780 nm to 860 nm.

Claim 82

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light: optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and a wavelength of light outputted by said first excitation light source ranges from 780 nm to 860 nm.

Claim 83

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and a wavelength of light outputted by said first excitation light source ranges from 780 nm to 860 nm.

Claim 84

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, and a wavelength of light outputted by said first excitation light source ranges from 780 nm to 860 nm.

Claim 85

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths; a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing the light outputted by said excitation light source into said first rare earth added optical fiber, and a wavelength of the light outputted by said first excitation light source ranges from 780 nm to 860 nm.

Claim 86

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths; a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing the light outputted by said excitation light source into said first rare earth added optical fiber, and a wavelength of the light outputted by said first excitation light source ranges from 780 nm to 860 nm.

Claim 87

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths; a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing the light outputted by said excitation light source into said first rare earth added optical fiber, and a wavelength of the light outputted by said first excitation light source ranges from 780 nm to 860 nm.

Claim 88

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light separator for separating said received light into light at respective wavelengths included in said light and for passing each separated light through each of said plurality of paths; a light combiner for wavelength multiplexing the light at the respective wavelengths each having propagated through each of said plurality of paths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light at a wavelength propagating through said path in accordance with control of said control means, said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths; a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing the light outputted by said excitation light source into said first rare earth added optical fiber, and a wavelength of the light outputted by said first excitation light source ranges from 780 nm to 860 nm.

Claim 89

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths; a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing the light outputted by said first excitation light source into said first rare earth added optical fiber, and a wavelength of the light outputted by said first excitation light source ranges from 780 nm to 860 nm.

Claim 90

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical power adjusting means coupled to receive said inputted light for amplifying or attenuating light at at least one wavelength included in said received light independently of the remaining light at wavelengths different from the wavelength of said light; optical amplifying means for amplifying said light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means and a gain of amplification performed by said optical amplifying means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths; a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing the light outputted by said first excitation light source into said first rare earth added optical fiber, and a wavelength of the light outputted by said first excitation light source ranges from 780 nm to 860 nm.

Claim 91

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths; a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing the light outputted by said first excitation light source into said first rare earth added optical fiber, and a wavelength of the light outputted by said first excitation light source ranges from 780 nm to 860 nm.

Claim 92

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light comprising: optical amplifying means for amplifying said inputted light; optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in the received light independently of the remaining light at wavelengths different from the wavelength of said light; and control means for controlling a gain of amplification performed by said optical amplifying means and a gain of amplification or attenuation performed by said optical power adjusting means, respectively, wherein: said optical power adjusting means includes: a plurality of paths for passing light therethrough; a light splitter for splitting said received light to pass each split light through each of said plurality of paths; a light combiner for extracting light at a particular wavelength from each light having propagated through each of said plurality of paths on each of said paths, and for wavelength multiplexing the extracted light at the respective wavelengths; and an optical gain adjuster arranged in at least one of said plurality of paths for amplifying or attenuating light propagating through said path in accordance with control of said control means, said optical gain adjuster includes: a first rare earth added optical fiber constituting part of said paths; a first excitation light source for outputting light for exciting said first rare earth added optical fiber; and a light combiner for said first excitation light source for introducing the light outputted by said first excitation light source into said first rare earth added optical fiber, and a wavelength of the light outputted by said first excitation light source ranges from 780 nm to 860 nm.

Claim 93

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light, comprising: first optical amplifying means for amplifying said inputted light: optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in said received light independently of light at wavelengths different from the wavelength of said light; a second optical amplifying means for amplifying the light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means a gain of amplification performed by said first optical amplifying means, and a gain of amplification performed by said second optical amplifying means, wherein: said first optical amplifying means includes: a first rare earth added optical fiber for passing said inputted light therethrough; an excitation light source for outputting light for exciting said first rare earth added optical fiber; splitting means for splitting the light outputted by said excitation light source; and a first light combiner for said excitation light source for introducing the light split by said splitting means into said first rare earth added optical fiber, and said second optical amplifying means includes: a second rare earth added optical fiber for passing therethrough the light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and a second light combiner for said excitation light source for introducing light different from the light split by said splitting means and introduced into said first rare earth added optical fiber, into said second rare earth added optical fiber.

Claim 94

An optical amplification apparatus for amplifying inputted light having signal light at a plurality of different wavelengths multiplexed thereon and outputting the amplified light, comprising: first optical amplifying means for amplifying said inputted light: optical power adjusting means coupled to receive said light amplified by said optical amplifying means for amplifying or attenuating light at at least one wavelength included in said received light independently of light at wavelengths different from the wavelength of said light; a second optical amplifying means for amplifying the light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and control means for controlling a gain of amplification or attenuation performed by said optical power adjusting means a gain of amplification performed by said first optical amplifying means, and a gain of amplification performed by said second optical amplifying means, wherein: said first optical amplifying means includes: a first rare earth added optical fiber for passing said inputted light therethrough; an excitation light source for outputting light for exciting said first rare earth added optical fiber; splitting means for splitting the light outputted by said excitation light source; and a first light combiner for said excitation light source for introducing the light split by said splitting means into said first rare earth added optical fiber, and said second optical amplifying means includes: a second rare earth added optical fiber for passing therethrough the light at the at least one wavelength amplified or attenuated by said optical power adjusting means; and a second light combiner for said excitation light source for introducing light different from the light split by said splitting means and introduced into said first rare earth added optical fiber, into said second rare earth added optical fiber.