Optical amplifier module

Claim 2

An optical amplifier module comprising: (a) a package for housing constituent elements; (b) an input optical fiber disposed on the input side of the module for guiding an input optical signal into the module; (c) an output optical fiber disposed on the output side of the module for taking out an output optical signal to the outside; (d) a semiconductor laser chip disposed between the input optical fiber and the output optical fiber for amplifying the input optical signal into the output optical signal; (e) first collimator means disposed between the input optical fiber and the semiconductor laser chip for collimating the input optical signal and for optically coupling the input optical fiber with the semiconductor laser chip through an input parallel light beam; (f) second collimator means disposed between the semiconductor laser chip and the ouput optical fiber for collimating the output optical signal and for optically coupling the semiconductor laser chip with the output optical fiber through an output parallel light beam; (g) first isolator means disposed in the input side of the semiconductor laser chip; and (h) second isolator means disposed in the output side of the semicondcutor laser chip.

Claim 3

An optical amplifier module according to Claim 1, wherein the first and second collimator means are two ball lenses, respectively, and the first and second isolator means are disposed between the two ball lenses.

Claim 4

An optical amplifier module according to Claim 1, wherein it further comprises filter means disposed on the output side of the semiconductor laser chip for cutting off spontaneous emission from the semiconductor laser chip.

Claim 5

An optical amplifier module according to Claim 1, wherein it further comprises monitor means disposed on the output side of the semiconductor laser chip for monitoring the output power of the semiconductor laser chip.

Claim 6

An optical amplifier module according to Claim 1, wherein it further comprises gain monitor means disposed on the input and output sides of the semiconductor laser chip for monitoring the output gain level of the semiconductor laser chip.

Claim 7

An optical amplifier module according to Claim 4, wherein the power monitor means includes a beam splitter disposed between the output fiber and the semiconductor laser chip for splitting the output light of the semiconductor laser chip, a photodiode for detecting and converting the light so splitted to an electric signal; and a collimating lens disposed between the beam splitter and the photodiode for collimating the light splitted and directing it onto the photodiode.

Claim 8

An optical amplifier module according to Claim 5, wherein the gain monitor means comprises first measuring means disposed on the input side of the semiconductor laser chip and second measuring means disposed on the output side of the same, the first measuring means including a beam splitter diposed between the input fiber and the semiconductor laser for splitting the input optical signal, a photodiode for detecting and converting the optical signal so splitted to an electric signal for determination of optical input power to the semiconductor laser chip, and a collimating lens disposed between the beam splitter and the photodiode for collimating the light splitted and directing it to the photodiode, the second measuring means including a beam splitter disposed between the output fiber and the semiconductor laser chip for splitting the output light from the semiconductor laser chip, a photodiode for detecting and converting the ouput light so splitted to an electric signal to determine optical output power of the semiconductor laser chip, and a collimating lens disposed between the beam splitter and the photodiode for collimating the light splitted and directing it to the photo diode, the optical input power and the optical output power specifying the output gain level of the semiconductor laser chip.

Claim 9

An optical amplifier module according to any of Claims 1, 3 and 4, wherein the second isolator means is located frontally of the filter means and the monitor means.

Claim 10

An optical amplifier module according to Claims 1, 3, 4, and 7, wherein the second isolator means is disposed frontally of the filter means and the second measuring means.

Claim 11

An optical amplifier module comprising: (a) a package for housing constituent elements; (b) an input optical fiber disposed on the input side of the module for guiding an input optical signal into the module; (c) an output optical fiber disposed on the output side of the module for taking out an output optical signal to the outside; (d) a semiconductor laser chip disposed between the input optical fiber and the output optical fiber for amplifying the input optical signal into the output optical singal; (e) first collimator means disposed between the input optical fiber and the semiconductor laser chip for collimating the input optical signal and for optically coupling the input optical fiber with the semiconductor laser chip through an input parallel light beam, the means including a first collimating lens disposed on the side of the input fiber and a second collimating lens disposd on the side of the semiconductor laser chip; (f) second collimator means disposed between the semiconductor laser chip and the ouput optical fiber for collimating the output optical signal and for optically coupling the semiconductor laser chip with the output optical fiber through an output parallel light beam, the collimator means including a third collimating lens disposed on the side of the semiconductor laser chip and a fourth collimating lens diposed on the side of the semiconductor laser chip; (g) first isolator means disposed between the first collimating lens and the second collimating lens; (h) second isolator means disposed between the third collimating lens and the fourth collimating lens; (i) first mounting means disposed on the input side of the module for mounting the input fiber and the first collimating lens; (j) second mounting means disposed on the middle portion of the module for mounting the semiconductor laser chip and the second and third collimating lenses; and (k) third mounting means disposed on the output side of the module for mounting the output fiber and the fourth collimating lens.

Claim 12

An optical amplifier module comprising: (a) a package for housing constituent elements; (b) an input optical fiber disposed on the input side of the module for guiding an input optical signal into the module; (c) an output optical fiber disposed on the output side of the module for taking out an output optical signal to the outside; (d) a semiconductor laser chip disposed between the input optical fiber and the output optical fiber for amplifying the input optical signal into the output optical singal; (e) first collimator means disposed between the input optical fiber and the semiconductor laser chip for collimating the input optical signal and for optically coupling the input optical fiber with the semiconductor laser chip through an input parallel light beam, the means including a first collimating lens disposed on the side of the input fiber and a second collimating lens disposd on the side of the semiconductor laser chip; (f) second collimator means disposed between the semiconductor laser chip and the ouput optical fiber for collimating the output optical signal and for optically coupling the semiconductor laser chip with the output optical fiber through an output parallel light beam, the collimator means including a third collimating lens disposed on the side of the semiconductor laser chip and a fourth collimating lens diposed on the side of the semiconductor laser chip; (g) first isolator means disposed between the first collimating lens and the second collimating lens; (h) second isolator means disposed between the third collimating lens and the fourth collimating lens; (i) first mounting means disposed on the input side of the module for mounting the input fiber and the first collimating lens; (j) second mounting means disposed on the middle portion of the module for mounting the semiconductor laser chip and the second and third collimating lenses; and (k) third mounting means disposed on the output side of the module for mounting the output fiber and the fourth collimating lens.

Claim 13

An optical amplifier module according to Claim 10, wherein it further comprises filter means inserted between the second isolator means and the fourth collimating lens for cutting off the spontaneous emission of the semiconductor laser chip.

Claim 14

An optical amplifier module according to Claim 10 and 11, wherein it further comprises monitor means inserted between the filter means and the fourth collimating lens for monitoring output optical power of the semiconductor laser chip.

Claim 15

An optical amplifier module according to Claim 10 and 11, wherein it further comprises gain monitor means disposed on the input and output sides of the semiconductor laser chip for monitoring the output gain level of the semiconductor laser chip.

Claim 16

An optical amplifier module according to Claim 12, wherein the power monitor means includes a beam splitter disposed between the output fiber and the semiconductor laser chip for splitting the output light of the semiconductor laser chip, a photo diode for detecting and converting the light so splitted to an electric signal; and a collimating lens disposed between the beam splitter and said photodiode for collimating the light splitted and directing it onto the photodiode.

Claim 17

An optical amplifier module according to Claim 13, wherein the gain monitor means comprises first measuring means disposed on the input side of the semiconductor laser chip and second measuring means disposed on the output side of the same, the first measuring means including a beam splitter disposed between the first isolator means and the second collimating lens for splitting the input optical signal, a photodiode for detecting and converting the optical signal so splitted to an elecric signal for determination of optical input power to the semiconductor laser chip, and a collimating lens disposed between the beam splitter and the photodiode for collimating the light splitted and directing it to the photodiode, the second measuring means including a beam splitter disposed between the output fiber and the semiconductor laser chip for splitting the output light from the semiconductor laser chip, a photodiode for detecting and converting the output light so splitted to an electric signal to determine optical output power from the semiconductor laser chip, and a collimating lens disposed between the beam splitter and the photodiode for collimating the light splitted and directing it to the photodiode, the optical input power and the optical output power specifying the output gain level of the semiconductor laser chip.