JPH043028A - Optical repeater - Google Patents
Optical repeaterInfo
- Publication number
- JPH043028A JPH043028A JP2104431A JP10443190A JPH043028A JP H043028 A JPH043028 A JP H043028A JP 2104431 A JP2104431 A JP 2104431A JP 10443190 A JP10443190 A JP 10443190A JP H043028 A JPH043028 A JP H043028A
- Authority
- JP
- Japan
- Prior art keywords
- optical
- output
- optical fiber
- signal
- fiber amplifier
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 55
- 239000013307 optical fiber Substances 0.000 claims abstract description 36
- 239000000835 fiber Substances 0.000 claims description 4
- 230000004936 stimulating effect Effects 0.000 claims 1
- 238000005086 pumping Methods 0.000 abstract 3
- 238000010586 diagram Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 230000006641 stabilisation Effects 0.000 description 3
- 238000011105 stabilization Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000032683 aging Effects 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 230000010355 oscillation Effects 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
- H01S3/13—Stabilisation of laser output parameters, e.g. frequency or amplitude
- H01S3/1301—Stabilisation of laser output parameters, e.g. frequency or amplitude in optical amplifiers
- H01S3/13013—Stabilisation of laser output parameters, e.g. frequency or amplitude in optical amplifiers by controlling the optical pumping
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/05—Construction or shape of optical resonators; Accommodation of active medium therein; Shape of active medium
- H01S3/06—Construction or shape of active medium
- H01S3/063—Waveguide lasers, i.e. whereby the dimensions of the waveguide are of the order of the light wavelength
- H01S3/067—Fibre lasers
- H01S3/06754—Fibre amplifiers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S3/00—Lasers, i.e. devices using stimulated emission of electromagnetic radiation in the infrared, visible or ultraviolet wave range
- H01S3/10—Controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation, e.g. switching, gating, modulating or demodulating
- H01S3/13—Stabilisation of laser output parameters, e.g. frequency or amplitude
- H01S3/1304—Stabilisation of laser output parameters, e.g. frequency or amplitude by using an active reference, e.g. second laser, klystron or other standard frequency source
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- Optics & Photonics (AREA)
- Optical Communication System (AREA)
- Light Guides In General And Applications Therefor (AREA)
- Lasers (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、光通信の光中継器に利用する。特に、光ファ
イバ増幅器を用いた光中継器に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is applied to an optical repeater for optical communications. In particular, it relates to an optical repeater using an optical fiber amplifier.
本発明は光中継器において、
光ファイバ増幅器のポンプ光源のバイアス電流を低周波
で変調し、その低周波成分の出力振幅に基づき光ファイ
バ増幅器の利得を自動制御することにより、
光中継器の入出力の利得が一定になるようにしたもので
ある。In an optical repeater, the present invention modulates the bias current of the pump light source of the optical fiber amplifier at a low frequency, and automatically controls the gain of the optical fiber amplifier based on the output amplitude of the low frequency component. The output gain is made constant.
従来、光中継器は、光ファイバ増幅器を使用した場合に
、光ファイバ増幅器の開発は近年盛んに行われているが
温度および経時などによる利得変化を補償する安定化技
術がまだ確立されていないためにその利得が安定してい
なかった。その安定化技術の一つとして、従来の光再生
中継器の光出力パワー安定化技術を用いて、ポンプ光源
の出力パワーをモニタし、一定化させる方法が考えられ
ていた。Conventionally, optical repeaters use optical fiber amplifiers, but although optical fiber amplifiers have been actively developed in recent years, stabilization technology that compensates for gain changes due to temperature and aging has not yet been established. That gain was not stable. As one of the stabilization techniques, a method has been considered in which the output power of the pump light source is monitored and stabilized using the conventional optical output power stabilization technique of an optical regenerator.
しかし、このような従来の光中継器では、ポンプ光源の
経時劣化などで光スペクトラムの変化や、発振中心波長
のずれを生じた場合に、ポンプ光源の出力パワーが一定
であっても、中継器としての利得が変化する欠点があっ
た。However, in such conventional optical repeaters, if the optical spectrum changes or the oscillation center wavelength shifts due to deterioration of the pump light source over time, even if the output power of the pump light source is constant, the repeater The disadvantage is that the gain varies.
本発明は上記の欠点を解決するもので、人８力の利得が
一定な光中継器を提供することを目的とする。The present invention solves the above-mentioned drawbacks, and aims to provide an optical repeater with a constant gain.
本発明は、光ファイバを介して人力する光信号を増幅す
る光ファイバ増幅器を備えた光中継器において、上記光
ファイバ増幅器のポンプ光源のバイアス電流を変調する
発振器と、上記光ファイバ増幅器の出力に接続された第
一の光合波器と、この第一の光合波器の出力光信号の一
つを検出して電気信号に変換する光検出器と、この光検
出器の出力信号のうちの上記発振器の出力周波数と同じ
周波数の信号を通過する帯域フィルタと、この帯域フィ
ルタの出力信号に基づき上記ポンプ電源のバイアス電流
を調整して上記光ファイバ増幅器の利得が一定になるよ
うに制御する自動利得制御回路とを備えたことを特徴と
する。The present invention provides an optical repeater equipped with an optical fiber amplifier that amplifies an optical signal manually inputted via an optical fiber, including an oscillator that modulates a bias current of a pump light source of the optical fiber amplifier, and an oscillator that modulates a bias current of a pump light source of the optical fiber amplifier; a connected first optical multiplexer, a photodetector that detects one of the output optical signals of the first optical multiplexer and converts it into an electrical signal, and one of the output signals of the photodetector. A bandpass filter that passes a signal of the same frequency as the output frequency of the oscillator, and an automatic gain that controls the gain of the optical fiber amplifier to be constant by adjusting the bias current of the pump power supply based on the output signal of this bandpass filter. It is characterized by comprising a control circuit.
また、本発明は、上記人力する光信号は１８５５μｍ帯
主信号であり、上記光ファイバ増幅器は、上記ポンプ電
源としてレーザ光を出力するレーザダイオードと、この
レーザ光と上記人力する１、５５μｍ帯主信号とを合波
する第二の光合波器と、この第二の光合波器の出力する
レーザ光で励起され誘導放出して上記人力する１、５５
μｍ帯主信号を増幅するエルビウムドープファイバとを
含むことができる。Further, in the present invention, the above-mentioned manually-powered optical signal is a 1855 μm band main signal, and the optical fiber amplifier includes a laser diode that outputs a laser beam as the pump power source, and a 1.55 μm-band main signal that is connected to the manually-powered optical signal. a second optical multiplexer that multiplexes the signals; and a laser beam excited by the laser beam output from the second optical multiplexer to perform stimulated emission and perform the above-mentioned manual operation 1,55.
and an erbium-doped fiber that amplifies the μm band main signal.
発振器は光ファイバ増幅器のポンプ光源のバイアス電流
を変調する。光検出器は光ファイバ増幅器の出力に接続
された第一の光合波器の出力光信号の一つを検出して電
気信号に変換する。帯域フィルタは光検出器の出力信号
のうちの発振器の出力周波数と同じ周波数の信号を通過
する。自動利得制御回路は帯域フィルタの出力信号に基
づきポンプ電源のバイアス電流を調整して光ファイバ増
幅器の利得が一定になるように制御する。The oscillator modulates the bias current of the pump light source of the optical fiber amplifier. The photodetector detects one of the output optical signals of the first optical multiplexer connected to the output of the optical fiber amplifier and converts it into an electrical signal. The bandpass filter passes a signal of the output signal of the photodetector having the same frequency as the output frequency of the oscillator. The automatic gain control circuit adjusts the bias current of the pump power supply based on the output signal of the bandpass filter to control the gain of the optical fiber amplifier to be constant.
以上の動作により光中継器の入出力の利得を一定にでき
る。By the above operation, the input/output gain of the optical repeater can be kept constant.
本発明の実施例について図面を参照して説明する。第１
図は本発明一実施例光中継器のブロック構成図である。Embodiments of the present invention will be described with reference to the drawings. 1st
The figure is a block diagram of an optical repeater according to an embodiment of the present invention.
第１図において、光中継器は、光ファイバを介して人力
する光信号を増幅する光ファイバ増幅器１０を備える。In FIG. 1, the optical repeater includes an optical fiber amplifier 10 that amplifies an optical signal input via an optical fiber.
光ファイバ増幅器１０のポンプ光源のバイアス電流を変
調する発振器４と、光ファイバ増幅器１０の出力に接続
された第一の光合波器として光合波器５と、光合波器５
の出力光信号の一つを検出して電気信号に変換する光検
出器としてホトダイオード６と、ホトダイオード６の出
力信号のうちの発振器４の出力周波数と同じ周波数の信
号を通過する帯域フィルタ８と、この帯域フィルタ８の
出力信号に基づき上記ポンプ電源のバイアス電流を調整
して光ファイバ増幅器１０の利得が一定になるように制
御する自動利得制御回路７とを備えたことを特徴とする
。An oscillator 4 that modulates the bias current of the pump light source of the optical fiber amplifier 10, an optical multiplexer 5 as a first optical multiplexer connected to the output of the optical fiber amplifier 10, and an optical multiplexer 5.
a photodiode 6 as a photodetector that detects one of the output optical signals of the photodiode 6 and converts it into an electrical signal; a bandpass filter 8 that passes a signal having the same frequency as the output frequency of the oscillator 4 among the output signals of the photodiode 6; The present invention is characterized in that it includes an automatic gain control circuit 7 that adjusts the bias current of the pump power source based on the output signal of the bandpass filter 8 so as to control the gain of the optical fiber amplifier 10 to be constant.
また、上８己入力する光信号は１．５５μｍ帯主信号で
あり、光ファイバ増幅器１０は、上記ポンプ電源として
レーザ光を出力するレーザダイオード３と、このレーデ
光と上記人力する１、５５μｍ帯主信号とを合波する第
二の光合波器として光合波器１と、光合波器１の出力す
るレーザ光で励起され誘導放出して上記入力する１、５
５μｍ帯主信号を増幅するエルビウムドープファイバ２
とを含む。The input optical signal is a 1.55 μm band main signal, and the optical fiber amplifier 10 has a laser diode 3 that outputs a laser beam as the pump power source, and a 1.55 μm band main signal that outputs the laser beam and the 1.55 μm band. An optical multiplexer 1 serves as a second optical multiplexer for multiplexing the main signal, and 1 and 5 which are excited by the laser light output from the optical multiplexer 1, stimulated emission, and input the above.
Erbium-doped fiber 2 that amplifies the 5μm band main signal
including.
このような構成の光中継器の動作について説明する。第
２図は本発明の光中継器の点Ａ、Ｂの１．５５μｍ帯主
信号波形を示す図である。The operation of the optical repeater having such a configuration will be explained. FIG. 2 is a diagram showing the 1.55 μm band main signal waveform at points A and B of the optical repeater of the present invention.
第２図（ａ）は点Ａの入力波形を示し、また第２図ら）
は点Ｂの正常動作時の波形を示し、さらに第２図（Ｃ）
は点Ｂの利得低下時の波形を示す図である。Figure 2(a) shows the input waveform at point A, and Figure 2(a) shows the input waveform at point A.
shows the waveform at point B during normal operation, and Fig. 2(C) shows the waveform at point B during normal operation.
2 is a diagram showing a waveform at point B when the gain decreases. FIG.
また、Ｖｏは入力端子、Ｖ＋ 、Ｖ２は出力電圧および
Ａ＋ 、Ａ２は低周波成分を示す。Further, Vo indicates an input terminal, V+ and V2 indicate output voltages, and A+ and A2 indicate low frequency components.
第１図において、いま、点Ａより第２図（ａ）に示す１
．５５μｍ帯主信号を入力すると発振器４は、ポンプ用
のレーザダイオード３のバイアス電流に低周波の変調を
かけ、光ファイバ増幅器１０の増幅度を変える。これに
より光ファイバ増幅器１０の出力光信号は、低周波の振
幅変調がかかる。点已における１、５５μｍ帯主信号波
形を第２図ら〕に示す。In Fig. 1, from point A, 1 shown in Fig. 2 (a)
．． When the 55 μm band main signal is input, the oscillator 4 applies low frequency modulation to the bias current of the pump laser diode 3 and changes the amplification degree of the optical fiber amplifier 10. As a result, the output optical signal of the optical fiber amplifier 10 is subjected to low frequency amplitude modulation. The waveform of the main signal in the 1.55 μm band at the point is shown in Fig. 2 et al.
光ファイバ増幅器１（］の出力光信号は、ホトダイオー
ド６で電気信号に変換され、さらに帯域フィルタ８で上
記変調をかけた低周波成分ＡＩ （第２図（ｂ）が抽
出される。この振幅情報が自動利得制御回路７に入力し
、自動利得制御回路７は、この低周波成分ＡＩを一定に
するようにポンプ用のレーザダイオード３のバイアス電
流を調節する。The output optical signal of the optical fiber amplifier 1 ( ) is converted into an electrical signal by the photodiode 6 , and further modulated by the bandpass filter 8 to extract the low frequency component AI (FIG. 2(b)). is input to the automatic gain control circuit 7, and the automatic gain control circuit 7 adjusts the bias current of the pump laser diode 3 so as to keep this low frequency component AI constant.
いま、光ファイバ増幅器１０の利得が何らかの理由で低
下したとすると、第１図に示す点已における１、５５μ
ｍ帯主信号波形は第２図（Ｃ）に示すようになり、
Ｖｌ： Ｖ２ ＝Ａ、 ： Ａ２
の関係にあることがわかる。この場合に自動利得制御回
路７の働きにより、ポンプ用のレーザダイオード３のバ
イアス電流を増加させ低周波成分Ａ２が低周波成分Ａ１
と同じになるように光ファイバ増幅器１０の利得を増
加させる。その結果第１図に示す点已における１、５５
μｍ帯主信号波形が第２図ら）に示すようになり、入８
力の利得（Ｖ、／ＶＯ）は一定となる。Now, if the gain of the optical fiber amplifier 10 decreases for some reason, the gain of 1,55μ at the point shown in FIG.
The m-band main signal waveform is as shown in FIG. 2(C), and it can be seen that the relationship is as follows: Vl: V2 = A, : A2. In this case, the automatic gain control circuit 7 increases the bias current of the pump laser diode 3 so that the low frequency component A2 becomes the low frequency component A1.
The gain of the optical fiber amplifier 10 is increased so that it becomes the same as . As a result, 1,55 at the point shown in Figure 1
The μm band main signal waveform becomes as shown in Figure 2, etc.
The force gain (V, /VO) remains constant.
以上説明したように、本発明は、光中継器の人出力の利
得を一定にできる優れた効果がある。As explained above, the present invention has the excellent effect of making the gain of the human output of the optical repeater constant.
第１図は本発明−実施例光中継器のブロック構成図。
第２図は本発明の光中継器の点Ａ、Ｂの１．５５μｍ帯
主信号波形を示す図。
１・・・光合波器、２・・・エルビウムドープファイバ
３・・・ポンプ用のレーザダイオード（１，４８μｍ帯
）、４・・・発振器、５・・・光分波器、６・・・ホト
ダイオード、７・・・自動利得制御回路、８・・・帯域
フィルタ、１０・・光ファイバ増幅器、Ａ１、Ａ２・・
・低周波成分、ｖ。
・・・入力電圧、Ｖ、 、Ｖ、・・・８カ電圧。FIG. 1 is a block diagram of an optical repeater according to an embodiment of the present invention. FIG. 2 is a diagram showing the 1.55 μm band main signal waveform at points A and B of the optical repeater of the present invention. DESCRIPTION OF SYMBOLS 1... Optical multiplexer, 2... Erbium-doped fiber 3... Laser diode for pump (1.48 μm band), 4... Oscillator, 5... Optical demultiplexer, 6... Photodiode, 7... Automatic gain control circuit, 8... Bandpass filter, 10... Optical fiber amplifier, A1, A2...
・Low frequency component, v. ... Input voltage, V, , V, ... 8 voltages.
Claims (1)
ァイバ増幅器を備えた光中継器において、上記光ファイ
バ増幅器のポンプ光源のバイアス電流を変調する発振器
と、 上記光ファイバ増幅器の出力に接続された第一の光合波
器と、 この第一の光合波器の出力光信号の一つを検出して電気
信号に変換する光検出器と、 この光検出器の出力信号のうちの上記発振器の出力周波
数と同じ周波数の信号を通過する帯域フィルタと、 この帯域フィルタの出力信号に基づき上記ポンプ電源の
バイアス電流を調整して上記光ファイバ増幅器の利得が
一定になるように制御する自動利得制御回路と を備えたことを特徴とする光中継器。 ２、上記入力する光信号は１．５５μｍ帯主信号であり
、上記光ファイバ増幅器は、上記ポンプ電源としてレー
ザ光を出力するレーザダイオードと、このレーザ光と上
記入力する１．５５μｍ帯主信号とを合波する第二の光
合波器と、この第二の光合波器の出力するレーザ光で励
起され誘導放出して上記入力する１．５５μｍ帯主信号
を増幅するエルビウムドープファイバとを含む請求項１
記載の光中継器。[Claims] 1. In an optical repeater equipped with an optical fiber amplifier that amplifies an optical signal input via an optical fiber, an oscillator that modulates a bias current of a pump light source of the optical fiber amplifier; a first optical multiplexer connected to the output of the amplifier; a photodetector that detects one of the output optical signals of the first optical multiplexer and converts it into an electrical signal; and an output signal of the photodetector. A bandpass filter that passes a signal having the same frequency as the output frequency of the oscillator, and a bias current of the pump power supply is adjusted based on the output signal of this bandpass filter so that the gain of the optical fiber amplifier is constant. An optical repeater characterized by comprising an automatic gain control circuit for controlling. 2. The input optical signal is a 1.55 μm band main signal, and the optical fiber amplifier includes a laser diode that outputs a laser beam as the pump power source, and a combination of this laser light and the input 1.55 μm band main signal. and an erbium-doped fiber that amplifies the input 1.55 μm band main signal by stimulating the laser beam output from the second optical multiplexer and performing stimulated emission. Item 1
The optical repeater described.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2104431A JPH043028A (en) | 1990-04-20 | 1990-04-20 | Optical repeater |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2104431A JPH043028A (en) | 1990-04-20 | 1990-04-20 | Optical repeater |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH043028A true JPH043028A (en) | 1992-01-08 |
Family
ID=14380487
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2104431A Pending JPH043028A (en) | 1990-04-20 | 1990-04-20 | Optical repeater |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH043028A (en) |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5274496A (en) * | 1992-01-20 | 1993-12-28 | Fujitsu Limited | Optical amplifying repeater with monitor and control function |
| US5363385A (en) * | 1992-03-19 | 1994-11-08 | Alcatel N.V. | Fiber-optic amplifier with control of the pump light wavelength |
| JPH06326666A (en) * | 1993-05-12 | 1994-11-25 | Nec Corp | Light direct amplifier |
| US5510926A (en) * | 1994-01-13 | 1996-04-23 | Alcatel N.V. | Transmission method and an optical link using multiplexing with application |
| US5801877A (en) * | 1995-07-06 | 1998-09-01 | Nec Corporation | Optical fiber amplifier for superimposing a sub-signal |
| US5926304A (en) * | 1996-03-15 | 1999-07-20 | Nec Corporation | Optical fiber amp repeater of amplifying an optical signal and superimposing an auxiliary signal |
| US7924499B2 (en) | 1998-03-19 | 2011-04-12 | Fujitsu Limited | Gain and signal level adjustments of cascaded optical amplifiers |
| US7969649B2 (en) | 1996-05-02 | 2011-06-28 | Fujitsu Limited | Controller which controls a variable optical attenuator to control the power level of a wavelength-multiplexed optical signal when the number of channels are varied |
| US8004752B2 (en) | 1996-05-28 | 2011-08-23 | Fujitsu Limited | Multi-wavelength light amplifier |
-
1990
- 1990-04-20 JP JP2104431A patent/JPH043028A/en active Pending
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5274496A (en) * | 1992-01-20 | 1993-12-28 | Fujitsu Limited | Optical amplifying repeater with monitor and control function |
| US5363385A (en) * | 1992-03-19 | 1994-11-08 | Alcatel N.V. | Fiber-optic amplifier with control of the pump light wavelength |
| JPH06326666A (en) * | 1993-05-12 | 1994-11-25 | Nec Corp | Light direct amplifier |
| US5510926A (en) * | 1994-01-13 | 1996-04-23 | Alcatel N.V. | Transmission method and an optical link using multiplexing with application |
| US5801877A (en) * | 1995-07-06 | 1998-09-01 | Nec Corporation | Optical fiber amplifier for superimposing a sub-signal |
| US5926304A (en) * | 1996-03-15 | 1999-07-20 | Nec Corporation | Optical fiber amp repeater of amplifying an optical signal and superimposing an auxiliary signal |
| US7969649B2 (en) | 1996-05-02 | 2011-06-28 | Fujitsu Limited | Controller which controls a variable optical attenuator to control the power level of a wavelength-multiplexed optical signal when the number of channels are varied |
| US8004752B2 (en) | 1996-05-28 | 2011-08-23 | Fujitsu Limited | Multi-wavelength light amplifier |
| US8320040B2 (en) | 1996-05-28 | 2012-11-27 | Fujitsu Limited | Multi-wavelength light amplifier |
| US8699126B2 (en) | 1996-05-28 | 2014-04-15 | Fujitsu Limited | Multi-wavelength light amplifier |
| US7969648B2 (en) | 1998-03-19 | 2011-06-28 | Fujitsu Limited | Gain and signal level adjustments of cascaded optical amplifiers |
| US7924499B2 (en) | 1998-03-19 | 2011-04-12 | Fujitsu Limited | Gain and signal level adjustments of cascaded optical amplifiers |
| US8547629B2 (en) | 1998-03-19 | 2013-10-01 | Fujitsu Limited | Gain and signal level adjustments of cascaded optical amplifiers |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2009430C (en) | Monitoring and/or control of optical amplifiers | |
| JPH03252231A (en) | Monitor system for optical repeater | |
| US5563731A (en) | Monitor control signal receiving apparatus for optical fiber amplifier | |
| US5566018A (en) | Apparatus for adjusting channel width of multi-channel fiber amplifier light source | |
| US6751014B2 (en) | Automatic gain control and dynamic equalization of erbium doped optical amplifiers in wavelength multiplexing networks | |
| US5809049A (en) | Method and apparatus for monitoring the RF drive circuit of a linear laser transmitter | |
| JPH043028A (en) | Optical repeater | |
| JPH0677565A (en) | Optical fiber amplifier and optical communication system using wavelength control of transmitter | |
| JP2001024594A (en) | Optical amplifier and system having the same | |
| US5479423A (en) | Method of modulating feedback signal in optical amplifier to compensate for pump laser saturation | |
| RU2146069C1 (en) | Method and erbium-doped optical-fiber amplifier for automatic tracking and filtering of wavelength of optical signal being transmitted | |
| US6721089B1 (en) | Method and apparatus for expanding the dynamic range of optical amplifiers | |
| US5768011A (en) | Optical amplifying repeater | |
| JP3134854B2 (en) | Optical amplifier | |
| JPH0764134A (en) | Output control circuit for optical amplifier | |
| JP3368935B2 (en) | Optical transmission equipment | |
| JPH06260709A (en) | Control method for optical amplifier and optical amplified multiple relay system | |
| JP2550895B2 (en) | Optical direct amplifier | |
| JPH0556034B2 (en) | ||
| JP2694803B2 (en) | Optical semiconductor laser device wavelength stabilization method | |
| JP3983510B2 (en) | Optical amplifier | |
| JP2798511B2 (en) | Optical repeater | |
| JPH11220197A (en) | Optical amplifier provided with gain control function | |
| JPH11122187A (en) | Optical transmitter and optical transmission method | |
| JP2673490B2 (en) | Optical noise source |