EP0415438A2
Expired / Lapsed
EP
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Optical amplifier and optical communication system provided with the optical amplifier
Assignee: Fujitsu Ltd
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Filing: 1990-08-31
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Granted: —
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Expires: 2010-08-31
Abstract
Abstract An optical communication system in which transmission of information with a pumping light beam acting as the carrier, in addition to transmission of information with a signal light beam, is made possible is disclosed. This optical communication system includes an optical fiber amplifier (24) adapted to amplify a signal light beam by having the signal light beam and a pumping light beam propagated through its rare-earth-doped fiber (28) doped with a rare earth element and a modulating circuit (48) for modulating the pumping light beam with a high-frequency modulating signal having a period shorter than the life span of fluorescence resulting from an excited state. In the case where the signal light beam and the pumping light beam are propagated in the same direction through the rare-earth-doped fiber, the transmission of information with the pumping light beam acting as the carrier can constitute a transmission of supervisory signal for an optical repeater, and in the case where the signal light beam and the pumping light beam are propagated in the directions opposite to each other through the rare-earth-doped fiber, a two-way transmission can be achieved by the transmission of information with the signal light beam and the transmission of information with the pumping light beam.
Inventors
- 👤 Masuo Suyama
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-28 00:11
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/29; H04B10/291; H01; H01S; H01S3/00; H01S3/10; H01S3/10007; H01S3/1001; H01S3/13; H01S3/1301; H01S3/13013; H04B10/07; H04B10/075; H04B10/077; H04B10/0777; H04B10/25; H04B10/2589; H04B10/2912; H04B10/293; H04B10/2931; H04B10/298; H01S3/05; H01S3/06; H01S3/063; H01S3/067; H01S3/06754; H01S3/06787; H04B2210/00; H04B2210/07; H04B2210/074
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
103 words
An optical amplifier including an optical fiber amplifier adapted to amplify a signal light beam by having the signal light beam and a pumping light beam propagated through its rare-earth-doped fiber doped with a rare earth element, comprising: a pumping light source for emitting a pumping light beam; and means for modulating said pumping light beam with a high-frequency modulating signal having a period shorter than the life span of fluorescence resulting from an excited state; whereby transmission of information with the pumping light beam acting as the carrier, in addition to transmission of information with the signal light beam, is made achievable.
Claim 2
Dependent Claim
103 words
An optical amplifier including an optical fiber amplifier adapted to amplify a signal light beam by having the signal light beam and a pumping light beam propagated through its rare-earth-doped fiber doped with a rare earth element, comprising: a pumping light source for emitting a pumping light beam; and means for modulating said pumping light beam with a high-frequency modulating signal having a period shorter than the life span of fluorescence resulting from an excited state; whereby transmission of information with the pumping light beam acting as the carrier, in addition to transmission of information with the signal light beam, is made achievable.
Claim 3
Dependent Claim
48 words
An optical amplifier according to claim 1, having a dichroic coupler for separating a pumping light beam modulated by information and input together with a signal light beam from the signal light beam and for combining another pumping light beam with the signal light beam for amplification thereof.
Claim 4
Dependent Claim
75 words
An optical amplifier according to claim 1, further including an optical coupler for splitting the output of said optical amplifier into portions in a predetermined ratio, filter means for removing pumping light beam component from one of the split portions of the output, and APC control means for controlling the average value of power of the pumping light source so that the output of the signal light beam may be kept at a predetermined value.
Claim 5
Dependent Claim
80 words
An optical amplifier according to claim 2, further including a receiver for receiving the pumping light beam modulated by information and separated from the signal light beam by said dichroic coupler, an agreement detector for detecting whether or not a set of address information received by said receiver agrees with a set of predetermined address information, and a controller for controlling a modulated signal, when the sets of information are in agreement, depending on the information received by said receiver.
Claim 6
Dependent Claim
108 words
An optical communication system having an optical repeater including an optical fiber amplifier adapted to amplify a signal light beam by having the signal light beam and a pumping light beam propagated through its rare-earth-doped fiber doped with a rare earth element, comprising: a pumping light source for emitting a pumping light beam; and means for modulating said pumping light beam with a high-frequency modulating signal having a period shorter than the life span of fluorescence resulting from an excited state; whereby transmission of information with the pumping light beam acting as the carrier, in addition to transmission of information with the signal light beam, is made achievable.
Claim 7
Dependent Claim
108 words
An optical communication system having an optical repeater including an optical fiber amplifier adapted to amplify a signal light beam by having the signal light beam and a pumping light beam propagated through its rare-earth-doped fiber doped with a rare earth element, comprising: a pumping light source for emitting a pumping light beam; and means for modulating said pumping light beam with a high-frequency modulating signal having a period shorter than the life span of fluorescence resulting from an excited state; whereby transmission of information with the pumping light beam acting as the carrier, in addition to transmission of information with the signal light beam, is made achievable.
Claim 8
Dependent Claim
52 words
An optical communication system according to claim 5, wherein said signal light beam and pumping light beam are propagated in the same direction through said rare-earth-doped fiber and the transmission of information with the pumping light beam acting as the carrier constitutes a transmission of a supervisory signal for said optical repeater.
Claim 9
Dependent Claim
61 words
An optical communication system according to claim 5, wherein said signal light beam and pumping light beam are propagated in the directions opposite to each other through said rare-earth-doped fiber, whereby a two-way transmission is made achievable by the transmission of information with said signal light beam and the transmission of information with said pumping light beam acting as the carrier.
Claim 10
Dependent Claim
99 words
An optical communication system comprising a first terminal station including an optical amplifier according to claim 1, first reception means for receiving a signal light beam amplified by said optical amplifier, and first transmission means for transmitting a modulated pumping light beam in the direction opposite to the signal light beam; and a second terminal station including second transmission means for outputting a signal light beam, a dichroic coupler for separating the pumping light beam from said first terminal station from the signal light beam, and second reception means for receiving the pumping light beam from said dichroic coupler.
References Cited (Backward Citations)
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