JPH09219696A - Optical amplifier - Google Patents
Optical amplifierInfo
- Publication number
- JPH09219696A JPH09219696A JP8026856A JP2685696A JPH09219696A JP H09219696 A JPH09219696 A JP H09219696A JP 8026856 A JP8026856 A JP 8026856A JP 2685696 A JP2685696 A JP 2685696A JP H09219696 A JPH09219696 A JP H09219696A
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- Prior art keywords
- optical
- signal light
- level
- wavelength
- output
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、波長多重化信号光
を一括増幅する光増幅装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical amplifying device for collectively amplifying wavelength multiplexed signal light.
【０００２】[0002]
【従来の技術】光増幅装置には、出力レベル一定制御方
式と利得一定制御方式がある。さらに出力レベル一定制
御方式には、励起光レベルを制御する方法と、励起光レ
ベルを一定に保ち信号光の入力または出力レベルを可変
光減衰器で制御する方法がある。ところで、励起光レベ
ルを変化させると波長に対する信号利得（ｄＧ／ｄλ）
も変化するので、波長多重化信号光を増幅する場合には
各波長に対する利得偏差が励起光レベルによって変化す
ることになる。したがって、波長多重化信号光の光増幅
装置としては、利得偏差が最も小さくなるように励起光
レベルを調整し、出力信号光レベルが一定になるように
可変光減衰器で制御する方法が適している。2. Description of the Related Art Optical amplifiers include a constant output level control system and a constant gain control system. Further, the constant output level control method includes a method of controlling the pumping light level and a method of keeping the pumping light level constant and controlling the input or output level of the signal light with a variable optical attenuator. By the way, when the pumping light level is changed, the signal gain with respect to the wavelength (dG / dλ)
Also changes, the gain deviation for each wavelength changes depending on the pumping light level when the wavelength-multiplexed signal light is amplified. Therefore, as an optical amplifier for wavelength-multiplexed signal light, a method of adjusting the pumping light level so that the gain deviation is minimized and controlling with a variable optical attenuator so that the output signal light level is constant is suitable. There is.
【０００３】図５は、従来の出力レベル一定制御方式に
よる光増幅装置の構成例を示す。図において、入力端子
１から入力された信号光は、光カプラ３−１，３−２を
介して、励起光源６−１から出力される励起光と合波さ
れて希土類添加ファイバ４−１に入力される。光カプラ
３−１で光パワーの一部が分岐された信号光は受光器５
−１に入力されて電気信号に変換される。希土類添加フ
ァイバ４−１から出力された信号光は、光カプラ３−
３、光アイソレータ８−１を介して可変光減衰器９に入
力される。光カプラ３−３で光パワーの一部が分岐され
た信号光は受光器５−２に入力されて電気信号に変換さ
れる。励起光源駆動回路７−１は、受光器５−１，５−
２の出力電圧から希土類添加ファイバ４−１における利
得を求め、その利得が一定になるように励起光源６−１
の出力レベルを制御する。FIG. 5 shows an example of the configuration of a conventional optical amplification apparatus using a constant output level control system. In the figure, the signal light input from the input terminal 1 is combined with the pumping light output from the pumping light source 6-1 via the optical couplers 3-1 and 3-2, and is coupled to the rare earth-doped fiber 4-1. Is entered. The signal light obtained by branching a part of the optical power by the optical coupler 3-1 is the light receiver 5
It is input to -1 and converted into an electric signal. The signal light output from the rare earth-doped fiber 4-1 is an optical coupler 3-
3, input to the variable optical attenuator 9 via the optical isolator 8-1. The signal light in which a part of the optical power is branched by the optical coupler 3-3 is input to the photodetector 5-2 and converted into an electric signal. The excitation light source drive circuit 7-1 includes the light receivers 5-1 and 5-.
The gain in the rare earth-doped fiber 4-1 is obtained from the output voltage of 2 and the pumping light source 6-1 is used so that the gain becomes constant.
Control the output level of the
【０００４】可変光減衰器９から出力された信号光は、
光カプラ３−４を介して希土類添加ファイバ４−２に入
力される。光カプラ３−４で光パワーの一部が分岐され
た信号光は受光器５−３に入力されて電気信号に変換さ
れる。希土類添加ファイバ４−２の出力側に接続された
光カプラ３−５は、励起光源６−２から出力される励起
光を希土類添加ファイバ４−２へ後方から入力する。希
土類添加ファイバ４−２から出力された信号光は、光カ
プラ３−５，３−６、光アイソレータ８−２を介して出
力端子２へ出力される。光カプラ３−６で光パワーの一
部が分岐された信号光は受光器５−４に入力されて電気
信号に変換される。The signal light output from the variable optical attenuator 9 is
It is input to the rare earth-doped fiber 4-2 via the optical coupler 3-4. The signal light in which a part of the optical power is branched by the optical coupler 3-4 is input to the light receiver 5-3 and converted into an electric signal. The optical coupler 3-5 connected to the output side of the rare earth-doped fiber 4-2 inputs the pumping light output from the pumping light source 6-2 into the rare earth-doped fiber 4-2 from the rear. The signal light output from the rare earth-doped fiber 4-2 is output to the output terminal 2 via the optical couplers 3-5 and 3-6 and the optical isolator 8-2. The signal light in which a part of the optical power is branched by the optical coupler 3-6 is input to the light receiver 5-4 and converted into an electric signal.
【０００５】光減衰量制御回路１０は、受光器５−４の
出力電圧に応じて可変光減衰器９の光減衰量を制御す
る。一方、励起光源駆動回路７−２は、受光器５−３，
５−４の出力電圧から希土類添加ファイバ４−２におけ
る利得を求め、その利得が一定になるように励起光源６
−２の出力レベルを制御する。これにより、希土類添加
ファイバ４−２への入力信号光レベルおよび励起光レベ
ルが一定となり、出力端子２の出力信号光レベルが一定
になるように制御される。The optical attenuation control circuit 10 controls the optical attenuation of the variable optical attenuator 9 according to the output voltage of the photo detector 5-4. On the other hand, the pumping light source drive circuit 7-2 includes the light receivers 5-3 and
The gain in the rare earth-doped fiber 4-2 is obtained from the output voltage of 5-4, and the pumping light source 6 is controlled so that the gain becomes constant.
-2 control the output level. As a result, the input signal light level and the pumping light level to the rare earth-doped fiber 4-2 become constant, and the output signal light level at the output terminal 2 is controlled to become constant.
【０００６】[0006]
【発明が解決しようとする課題】ところで、波長多重化
信号光を伝送する光システムでは、必要に応じて各波長
の信号光の遮断や立ち上げを行う。このとき、光増幅装
置へ入力される信号光の数（チャネル数）が変化する
が、その全出力信号光レベルを一定に保つ制御を行うと
１波長あたりの信号光レベルが変動する。すなわち、出
力レベル一定制御方式の光増幅装置では、波長多重数が
変化すると各信号光の光レベルが変化する問題点があっ
た。この信号光レベルの変動は伝送特性の劣化を招き、
伝送情報に誤りを生じさせる原因となる。By the way, in an optical system for transmitting wavelength-multiplexed signal light, the signal light of each wavelength is cut off or activated as necessary. At this time, the number of signal lights (number of channels) input to the optical amplifier changes, but if control is performed to keep the total output signal light level constant, the signal light level per wavelength changes. That is, the optical amplifier of the constant output level control system has a problem that the optical level of each signal light changes when the number of wavelength division multiplexing changes. This fluctuation of the signal light level causes deterioration of transmission characteristics,
It causes an error in the transmission information.
【０００７】一方、利得一定制御方式の光増幅装置で
は、波長多重数が変化しても各信号光の光レベルを一定
に保つことができるが、出力信号光レベルを一定にする
には入力信号光レベルも一定レベルとする必要がある。
しかし、一般の光部品を組み合わせて構成する光システ
ムでは、入力信号光レベルを一定レベルに均一化するこ
とは実用上困難であった。それは、受動系光部品では挿
入損失のバラツキがありまた経年変化等によっても損失
が変化し、能動系光部品では出力光強度にバラツキがあ
るためである。さらに、中継光システムでは、中継間隔
が一定ではないので入力光強度も一定ではない。入力光
強度の範囲は20dB以上になることもある。On the other hand, in the constant gain control type optical amplifier, the optical level of each signal light can be kept constant even if the number of wavelength division multiplexing changes. The light level also needs to be constant.
However, in an optical system configured by combining general optical components, it is practically difficult to make the input signal light level uniform. This is because the passive optical components have variations in insertion loss, the losses also change due to aging, and the active optical components have variations in output light intensity. Further, in the relay optical system, the input light intensity is not constant because the relay interval is not constant. The range of input light intensity may be 20 dB or more.
【０００８】本発明は、波長多重化信号光を一括増幅す
る際に、チャネル数の変動や入力信号光レベルの変化に
対して、その全信号光レベルを一定に保つのではなく、
各チャネルの信号光レベルの平均値を一定にできる光増
幅装置を提供することを目的とする。According to the present invention, when the wavelength-multiplexed signal light is collectively amplified, the total signal light level is not kept constant with respect to the fluctuation of the number of channels and the change of the input signal light level.
An object of the present invention is to provide an optical amplifying device capable of keeping the average value of the signal light level of each channel constant.
【０００９】[0009]
【課題を解決するための手段】本発明の光増幅装置は、
利得一定制御を行う光ファイバ増幅器を２段縦続接続
し、所定の位置に可変光減衰手段を挿入した構成におい
て、信号光レベルと波長多重数（チャネル数）を検出
し、さらに各波長（各チャネル）の信号光レベルの平均
値を求め、それが一定になるように可変光減衰手段の光
減衰量を制御する。The optical amplifying device of the present invention comprises:
In a configuration in which two optical fiber amplifiers that perform constant gain control are cascaded and variable optical attenuating means is inserted at a predetermined position, the signal light level and the wavelength multiplexing number (the number of channels) are detected, and each wavelength (each channel) is detected. The average value of the signal light level in 1) is obtained, and the optical attenuation amount of the variable optical attenuating means is controlled so that it becomes constant.
【００１０】[0010]
【発明の実施の形態】図１は、本発明の光増幅装置の実
施形態を示す。本実施形態は、図５の従来構成と同様
に、利得一定制御を行う光ファイバ増幅器を２段縦続に
接続し、その間に可変光減衰器９を挿入して出力レベル
一定制御を行う構成を基本とする。なお、可変光減衰器
９は入力端子１または出力端子２の位置にあってもよい
が、本実施形態における位置が出力レベル一定制御に最
も都合がよい。本実施形態の特徴は、可変光減衰器９の
光減衰量を制御する際に、各チャネルの信号光レベルの
平均値が一定になるように制御するところにある。FIG. 1 shows an embodiment of an optical amplifying device according to the present invention. In the present embodiment, similar to the conventional configuration shown in FIG. 5, the optical fiber amplifiers that perform constant gain control are connected in two stages in series, and the variable optical attenuator 9 is inserted between them to perform constant output level control. And The variable optical attenuator 9 may be located at the input terminal 1 or the output terminal 2, but the position in the present embodiment is most convenient for constant output level control. A feature of this embodiment is that when the optical attenuation amount of the variable optical attenuator 9 is controlled, the average value of the signal light level of each channel is controlled to be constant.
【００１１】波長多重数検出回路１１は、受光器５−１
から出力される電気信号を入力し、入力信号光の波長多
重数ｉに比例した電圧Ｖ(i) を出力する。受光器５−３
は、可変光減衰器９の出力信号光の光パワーの一部を光
カプラ３−４を介して入力し、その信号光レベルに比例
した電圧Ｖ(P) を出力する。平均レベル検出回路１２は
波長多重数検出回路１１の出力電圧Ｖ(i) と受光器５−
３の出力電圧Ｖ(P) を入力し、各チャネルの信号光レベ
ルの平均値に比例した電圧Ｖ(P/i) を出力する。光減衰
量制御回路１０は、平均レベル検出回路１２の出力電圧
Ｖ(P/i) に応じて可変光減衰器９の光減衰量を制御す
る。The wavelength multiplex number detection circuit 11 includes a light receiver 5-1.
The electric signal output from the input terminal is input, and a voltage V (i) proportional to the wavelength multiplexing number i of the input signal light is output. Light receiver 5-3
Inputs a part of the optical power of the output signal light of the variable optical attenuator 9 through the optical coupler 3-4 and outputs a voltage V (P) proportional to the signal light level. The average level detection circuit 12 outputs the output voltage V (i) of the wavelength multiplex number detection circuit 11 and the light receiver 5-
The output voltage V (P) of No. 3 is input, and the voltage V (P / i) proportional to the average value of the signal light level of each channel is output. The optical attenuation amount control circuit 10 controls the optical attenuation amount of the variable optical attenuator 9 according to the output voltage V (P / i) of the average level detection circuit 12.
【００１２】なお、本実施形態の平均レベル検出回路１
２は、可変光減衰器９の出力信号光レベル（Ｖ(P))をモ
ニタする構成になっているが、可変光減衰器９の入力信
号光レベル、または入力端子１の入力信号光レベル、ま
たは出力端子２の出力信号光レベルをモニタする構成で
もよい。図２は、波長多重数検出回路１１の構成例を示
す。本構成例は、波長に固有の周波数で微弱に強度変調
されたパイロット・トーン（ＰＬＴ）が信号光に重畳さ
れている場合のものである。The average level detection circuit 1 of the present embodiment
2 is configured to monitor the output signal light level (V (P)) of the variable optical attenuator 9, the input signal light level of the variable optical attenuator 9 or the input signal light level of the input terminal 1, Alternatively, the configuration may be such that the output signal light level of the output terminal 2 is monitored. FIG. 2 shows a configuration example of the wavelength multiplexing number detection circuit 11. This configuration example is for a case where a pilot tone (PLT) weakly intensity-modulated at a frequency peculiar to the wavelength is superimposed on the signal light.
【００１３】波長多重数検出回路１１に入力される電気
信号は、最大入力チャネル数Ｍに分配され、各ＰＬＴ周
波数f1，f2，…，fMに対応したバンドパスフィルタ（Ｂ
ＰＦ）２１−１〜２１−Ｍを介して、各チャネルのＰＬ
Ｔ振幅レベルが検出される。このとき、入力されていな
いチャネルのＰＬＴ振幅レベルは０であり、入力されて
いるチャネルのＰＬＴ振幅レベルには所定の振動成分が
現れる。各バンドパスフィルタ２１−１〜２１−Ｍの出
力は、それぞれ比較回路２２−１〜２２−Ｍに入力さ
れ、光増幅装置への所定の最小入力レベルとの大小が判
定される。すなわち、入力されているチャネルについて
は“１”に対応する電圧が出力される。加算器２３は、
この“１”に対応する電圧を加算し、入力信号光の波長
多重数（入力チャネル数）ｉに比例したアナログ電圧Ｖ
(i) を出力する。[0013] electric signal input to the wavelength multiplex number detecting circuit 11 is distributed to the maximum number of input channels M, the PLT frequency f 1, f 2, ..., band pass filter (B corresponding to f M
PF) 21-1 to 21-M through PL of each channel
The T amplitude level is detected. At this time, the PLT amplitude level of the non-input channel is 0, and a predetermined vibration component appears in the PLT amplitude level of the input channel. The outputs of the bandpass filters 21-1 to 21-M are input to the comparison circuits 22-1 to 22-M, respectively, and the magnitude of the output is compared with a predetermined minimum input level to the optical amplifier. That is, the voltage corresponding to "1" is output for the input channel. The adder 23 is
An analog voltage V proportional to the wavelength multiplexing number (input channel number) i of the input signal light is obtained by adding the voltage corresponding to “1”.
Output (i).
【００１４】なお、ＰＬＴ振幅レベルはバンドパスフィ
ルタ２１を用いて検出する他に、同期検波回路を用いて
検出することも可能である。また、ここではアナログ回
路による構成例を示したが、同様の動作をディジタル的
に実現することも容易である。また、ＰＬＴを用いない
場合には、光カプラ３−１で分岐された信号光を入力
し、光分波器で各波長の信号光に分波し、それぞれの光
強度を検出することにより、波長多重数（入力チャネル
数）ｉに比例した電圧Ｖ(i) を出力させることもでき
る。The PLT amplitude level can be detected by using a synchronous detection circuit instead of using the bandpass filter 21. Further, although the configuration example using the analog circuit is shown here, it is easy to realize the same operation digitally. When the PLT is not used, the signal light branched by the optical coupler 3-1 is input, the signal light is demultiplexed into the signal light of each wavelength by the optical demultiplexer, and the respective light intensities are detected. It is also possible to output a voltage V (i) proportional to the number of wavelength division multiplexing (the number of input channels) i.
【００１５】図３は、光減衰量制御回路１０および可変
光減衰器９の構成例を示す。ここでは、可変光減衰器９
としてシリカ系光導波路によって形成したマッハツェン
ダ干渉計を用いた例を示す。マッハツェンダ干渉計は、
２つの方向性結合器３１，３２の間に２本の光導波路３
３，３４を接続し、その一方の光導波路にヒータ３５を
蒸着した構成である。ヒータ３５に流す電流に応じた熱
光学効果により光導波路の屈折率が変化してスイッチ動
作する。高いオン／オフ比を確保するために、２本のア
ーム長が異なる非対称型としている。ヒータ３５に流す
電流がゼロのときには光減衰量はゼロとなる。また、図
１における可変光減衰器９と光カプラ３−４は、図３の
ようにシリカ系基板上に集積化することができ、損失お
よび形状を小さくすることができる。FIG. 3 shows a configuration example of the optical attenuation control circuit 10 and the variable optical attenuator 9. Here, the variable optical attenuator 9
As an example, an example using a Mach-Zehnder interferometer formed by a silica optical waveguide is shown. The Mach-Zehnder interferometer
Two optical waveguides 3 are provided between the two directional couplers 31 and 32.
3, 34 are connected, and the heater 35 is vapor-deposited on one of the optical waveguides. The thermo-optic effect according to the electric current flowing through the heater 35 changes the refractive index of the optical waveguide to perform the switch operation. In order to secure a high on / off ratio, the two arm lengths are made asymmetrical. When the current passed through the heater 35 is zero, the light attenuation amount is zero. Further, the variable optical attenuator 9 and the optical coupler 3-4 in FIG. 1 can be integrated on the silica-based substrate as shown in FIG. 3, and the loss and the shape can be reduced.
【００１６】光減衰量制御回路１０は、平均値一定制御
回路４０と定電流回路５０により構成される。平均値一
定制御回路４０に入力される平均値電圧Ｖ(P/i) は、オ
ペアンプ４１で基準電圧Ｖref と比較され、その差分電
圧Δν（＝ＡNF（Ｖ(P/i) −Ｖref)がオペアンプ４２を
用いた加算器に入力され、基準電圧Ｖref と加算されて
定電流回路５０に入力される。定電流回路５０は、オペ
アンプ５１とトランジスタ５２によって構成され、Δν
が正値であればヒータ３５へ流れる電流を増加させる。
一方、Δνが負値であればヒータ３５へ流れる電流が減
少する。ともに光減衰量が大きくなり、モニタ光強度
（Ｖ(P))が小さくなってΔνがゼロに近づく。このよう
な負帰還動作により、可変光減衰器９から出力される各
チャネルの信号光レベルの平均値が一定になるように制
御することができる。The optical attenuation control circuit 10 comprises a constant average value control circuit 40 and a constant current circuit 50. The average value voltage V (P / i) input to the constant average value control circuit 40 is compared with the reference voltage Vref by the operational amplifier 41, and the difference voltage Δν (= A NF (V (P / i) −Vref) is calculated. It is input to the adder using the operational amplifier 42, is added to the reference voltage Vref, and is input to the constant current circuit 50. The constant current circuit 50 is composed of an operational amplifier 51 and a transistor 52.
Is positive, the current flowing to the heater 35 is increased.
On the other hand, if Δν is a negative value, the current flowing to the heater 35 decreases. In both cases, the amount of light attenuation increases, the monitor light intensity (V (P)) decreases, and Δν approaches zero. By such a negative feedback operation, it is possible to control so that the average value of the signal light level of each channel output from the variable optical attenuator 9 becomes constant.
【００１７】図４は、光減衰量制御回路１０の他の構成
例を示す。ここでは、図３の平均値一定制御回路４０の
処理を演算回路を用いて行う構成を示す。光減衰量制御
回路１０は、平均レベル検出回路１２の出力電圧Ｖ(P/
i)をディジタル信号に変換するＡ／Ｄ変換器４３と、平
均値電圧Ｖ(P/i) と基準電圧Ｖref の差分を演算する演
算回路４４と、演算回路４４の出力値をアナログ信号に
変換して定電流回路５０に与えるＤ／Ａ変換器４５によ
り構成される。なお、演算回路４４では、定電流回路５
０への印加電圧と、可変光減衰器９における光減衰量と
の関係を予めメモリに記憶させておくことにより演算処
理が簡単になる。FIG. 4 shows another configuration example of the optical attenuation control circuit 10. Here, a configuration is shown in which the processing of the average value constant control circuit 40 of FIG. 3 is performed using an arithmetic circuit. The optical attenuation amount control circuit 10 outputs the output voltage V (P / P / V of the average level detection circuit 12
i) is converted into a digital signal, an A / D converter 43, an arithmetic circuit 44 for calculating the difference between the average value voltage V (P / i) and the reference voltage Vref, and an output value of the arithmetic circuit 44 is converted into an analog signal. The D / A converter 45 is provided to the constant current circuit 50. In the arithmetic circuit 44, the constant current circuit 5
By storing the relationship between the applied voltage to 0 and the optical attenuation amount in the variable optical attenuator 9 in the memory in advance, the arithmetic processing is simplified.
【００１８】[0018]
【発明の効果】以上説明したように、本発明の光増幅装
置は、波長多重化信号光のチャネル数や各チャネルの入
力信号光レベルが変化しても、各チャネルの信号光レベ
ルの平均値を一定に制御することができる。As described above, the optical amplifying device of the present invention has an average value of the signal light level of each channel even if the number of channels of the wavelength multiplexed signal light or the input signal light level of each channel changes. Can be controlled to be constant.
【図１】本発明の光増幅装置の実施形態を示す図。FIG. 1 is a diagram showing an embodiment of an optical amplifying device of the invention.
【図２】波長多重数検出回路１１の構成例を示す図。FIG. 2 is a diagram showing a configuration example of a wavelength multiplex number detection circuit 11.
【図３】光減衰量制御回路１０および可変光減衰器９の
構成例を示す図。FIG. 3 is a diagram showing a configuration example of an optical attenuation control circuit 10 and a variable optical attenuator 9.
【図４】光減衰量制御回路１０の他の構成例を示す図。FIG. 4 is a diagram showing another configuration example of the optical attenuation control circuit 10.
【図５】従来の出力レベル一定制御方式による光増幅装
置の構成例を示す図。FIG. 5 is a diagram showing an example of the configuration of a conventional optical amplification device using a constant output level control method.
１ 入力端子 ２ 出力端子 ３ 光カプラ ４ 希土類添加ファイバ ５ 受光器 ６ 励起光源 ７ 励起光源駆動回路 ８ 光アイソレータ ９ 可変光減衰器 １０ 光減衰量制御回路 １１ 波長多重数検出回路 １２ 平均レベル検出回路 ２１ バンドパスフィルタ（ＢＰＦ） ２２ 比較回路 ２３ 加算器 ３１，３２ 方向性結合器 ３３，３４ 光導波路 ３５ ヒータ ４０ 平均値一定制御回路 ４１，４２ オペアンプ ４３ Ａ／Ｄ変換器 ４４ 演算回路 ４５ Ｄ／Ａ変換器 ５０ 定電流回路 ５１ オペアンプ ５２ トランジスタ 1 Input Terminal 2 Output Terminal 3 Optical Coupler 4 Rare Earth Doped Fiber 5 Photoreceptor 6 Excitation Light Source 7 Excitation Light Source Drive Circuit 8 Optical Isolator 9 Variable Optical Attenuator 10 Optical Attenuation Control Circuit 11 Wavelength Multiplexing Detection Circuit 12 Average Level Detection Circuit 21 Band pass filter (BPF) 22 Comparing circuit 23 Adder 31, 32 Directional coupler 33, 34 Optical waveguide 35 Heater 40 Average value constant control circuit 41, 42 Operational amplifier 43 A / D converter 44 Arithmetic circuit 45 D / A conversion Device 50 constant current circuit 51 operational amplifier 52 transistor
Claims (3)
添加ファイバと、 第１および第２の励起光をそれぞれ前記第１および第２
の希土類添加ファイバに入力し、かつ前記第１および第
２の希土類添加ファイバの利得がそれぞれ一定になるよ
うに励起光パワーを制御する第１および第２の励起光入
力手段と、 前記第１の希土類添加ファイバの入力端から前記第２の
希土類添加ファイバの出力端までの間の所定の位置に挿
入される可変光減衰手段とを備え、 前記第１の光ファイバへ波長多重された信号光が入力さ
れ、前記第２の光ファイバから増幅された信号光が出力
される光増幅装置において、 前記信号光の光レベルを検出する信号光レベル検出手段
と、 前記信号光の波長多重数を検出する波長多重数検出手段
と、 前記各検出手段で検出された信号光レベルと波長多重数
を入力し、各波長の信号光レベルの平均値が一定になる
ように前記可変光減衰手段の光減衰量を制御する光減衰
量制御手段とを備えたことを特徴とする光増幅装置。1. A first and a second rare earth-doped fibers that are cascade-connected, and a first and a second pumping light, respectively.
First and second pumping light input means for controlling pumping light power so that the gains of the first and second rare earth-doped fibers become constant, respectively. A variable optical attenuator inserted at a predetermined position between the input end of the rare earth-doped fiber and the output end of the second rare earth-doped fiber, wherein the signal light wavelength-multiplexed to the first optical fiber is In an optical amplifying device that outputs the signal light that is input and amplified from the second optical fiber, a signal light level detection unit that detects an optical level of the signal light, and a wavelength multiplexing number of the signal light is detected. Wavelength multiplex number detection means, the signal light level detected by each of the detection means and the wavelength multiplex number are input, and the optical attenuation amount of the variable optical attenuating means so that the average value of the signal light level of each wavelength becomes constant. To Optical amplifying apparatus being characterized in that an optical attenuation control means Gosuru.
減衰量制御手段は、 信号光レベルを波長多重数で割算して各波長の信号光レ
ベルの平均値を検出する平均レベル検出回路と、 前記平均レベル検出回路の出力と基準値とを比較し、そ
の差分値に応じて可変光減衰手段の光減衰量を制御する
光減衰量制御回路とを備えたことを特徴とする光増幅装
置。2. An optical level control circuit in the optical amplification device according to claim 1, wherein the optical attenuation amount control means divides the signal light level by the number of wavelength multiplexes and detects an average value of the signal light level of each wavelength. And an optical attenuation amount control circuit that compares the output of the average level detection circuit with a reference value and controls the optical attenuation amount of the variable optical attenuation means according to the difference value. apparatus.
変光減衰手段は、 シリカ系基板上に形成した導波路型干渉計に熱光学効果
による導波路屈折率変化を生じさせて可変光減衰機能を
実現した構成であることを特徴とする光増幅装置。3. The variable optical attenuating means in the optical amplifying device according to claim 1, wherein the waveguide optical interferometer formed on a silica-based substrate is caused to undergo a waveguide optical index change due to a thermo-optical effect, and the variable optical attenuating is performed. An optical amplifying device having a configuration that realizes a function.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8026856A JPH09219696A (en) | 1996-02-14 | 1996-02-14 | Optical amplifier |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8026856A JPH09219696A (en) | 1996-02-14 | 1996-02-14 | Optical amplifier |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09219696A true JPH09219696A (en) | 1997-08-19 |
Family
ID=12204928
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8026856A Pending JPH09219696A (en) | 1996-02-14 | 1996-02-14 | Optical amplifier |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH09219696A (en) |
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| WO2001010063A1 (en) * | 1999-07-30 | 2001-02-08 | Mitsubishi Denki Kabushiki Kaisha | Optical amplification repeater and optical amplification repeating and transmitting system |
| KR100358115B1 (en) * | 2000-12-14 | 2002-10-25 | 한국전자통신연구원 | Dynamic gain-controlled erbium-doped fiber amplifier |
| KR100358112B1 (en) * | 2000-12-26 | 2002-10-25 | 한국전자통신연구원 | Gain clamped erbium-doped fiber amplifier |
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