JPH0730520A - Optical fiber amplifier for wavelength multiplex transmission - Google Patents
Optical fiber amplifier for wavelength multiplex transmissionInfo
- Publication number
- JPH0730520A JPH0730520A JP5171342A JP17134293A JPH0730520A JP H0730520 A JPH0730520 A JP H0730520A JP 5171342 A JP5171342 A JP 5171342A JP 17134293 A JP17134293 A JP 17134293A JP H0730520 A JPH0730520 A JP H0730520A
- Authority
- JP
- Japan
- Prior art keywords
- optical
- signal light
- signal
- amplification factor
- 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.)
- Granted
Links
- 239000013307 optical fiber Substances 0.000 title claims abstract description 51
- 230000005540 biological transmission Effects 0.000 title claims abstract description 27
- 230000003287 optical effect Effects 0.000 claims abstract description 132
- 230000003321 amplification Effects 0.000 claims abstract description 33
- 238000003199 nucleic acid amplification method Methods 0.000 claims abstract description 33
- 239000000284 extract Substances 0.000 claims description 3
- 238000006243 chemical reaction Methods 0.000 claims 1
- 230000002238 attenuated effect Effects 0.000 abstract description 3
- 239000000835 fiber Substances 0.000 description 3
- 238000013016 damping Methods 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 239000004973 liquid crystal related substance Substances 0.000 description 2
- 238000002834 transmittance Methods 0.000 description 2
- 229910052691 Erbium Inorganic materials 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- UYAHIZSMUZPPFV-UHFFFAOYSA-N erbium Chemical compound [Er] UYAHIZSMUZPPFV-UHFFFAOYSA-N 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 230000005693 optoelectronics Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
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- Optical Communication System (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は光ファイバ増幅器に係わ
り、特に多重化された各信号光ごとに出力レベルを制御
できる波長多重伝送用光ファイバ増幅器に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber amplifier, and more particularly to an optical fiber amplifier for wavelength division multiplexing transmission capable of controlling an output level for each multiplexed signal light.
【０００２】[0002]
【従来の技術】複数の相異なる波長の信号光を１本の光
ファイバで伝送する波長分割多重伝送システムでは、こ
れらの信号光の波長多重化と直接増幅を併せて行う波長
多重伝送用光ファイバ増幅器を用いることができる。2. Description of the Related Art In a wavelength division multiplex transmission system for transmitting a plurality of signal lights having different wavelengths through one optical fiber, an optical fiber for wavelength multiplex transmission for performing both wavelength multiplexing and direct amplification of these signal lights. An amplifier can be used.
【０００３】図２は、従来提案されたこのような波長多
重伝送用光ファイバ増幅器およびその周辺の構成を表わ
したものである。この波長多重伝送用光ファイバ増幅器
は、２つ以上の相異なる波長の信号光を多重化するとと
もにこれらを増幅するようになっている。第１〜第ｎの
光送信器１１1 〜１１n はそれぞれλ1 〜λn の互いに
異なった波長の信号光を送出するようになっており、こ
れらの信号光は波長多重伝送用光ファイバ増幅器１２に
入力されるようになっている。波長多重伝送用光ファイ
バ増幅器１２は、これらの信号光を入力して合波する光
合波器１３とこれらの出力を直接増幅する光ファイバ増
幅器１４を備えている。光ファイバ増幅器１４の出力側
には光分岐器１５が配置されていて、これによって分岐
された一部の出力は光−電気変換器１６に入力されて電
気信号に変換され、この電気信号が光ファイバ増幅器１
４にフィードバックされている。FIG. 2 shows the structure of a conventionally proposed optical fiber amplifier for wavelength division multiplexing and its surroundings. This optical fiber amplifier for wavelength division multiplexing is designed to multiplex two or more signal lights having different wavelengths and to amplify them. It is adapted to the optical transmitter 11 1 to 11 n of first through n sends the signal light of different wavelengths to each other lambda 1 to [lambda] n, respectively, these signal light wavelength multiplexing transmission optical fiber amplifier 12 is input. The optical fiber amplifier 12 for wavelength division multiplex transmission includes an optical multiplexer 13 for inputting and multiplexing these signal lights and an optical fiber amplifier 14 for directly amplifying these outputs. An optical branching device 15 is arranged on the output side of the optical fiber amplifier 14. A part of the output branched by the optical branching device 15 is input to an optical-electrical converter 16 and converted into an electric signal, and the electric signal is converted into an optical signal. Fiber amplifier 1
It is fed back to 4.
【０００４】このような構成の波長多重伝送用光ファイ
バ増幅器１２で、入力されたｎ個の信号光は光合波器１
３で波長多重化される。多重化された信号光は光ファイ
バ増幅器１４で増幅されたのち光分岐器１５を経て出力
されるが、その一部は光−電気変換器１６で電気信号に
変換されたのち、光ファイバ増幅器１４の増幅率を制御
するのに用いられる。この制御は多重化された信号光が
所定の光出力レベルになるように施される制御である。In the optical fiber amplifier 12 for wavelength division multiplex transmission having the above-mentioned structure, the input n signal lights are input to the optical multiplexer 1.
3 is wavelength-multiplexed. The multiplexed signal light is amplified by the optical fiber amplifier 14 and then output through the optical branching device 15. A part of the signal light is converted into an electric signal by the optical-electrical converter 16 and then the optical fiber amplifier 14 is output. It is used to control the amplification factor of. This control is performed so that the multiplexed signal light has a predetermined optical output level.
【０００５】このような波長多重伝送用光ファイバ増幅
器では、信号光の間の利得競合が発生する。このため、
光送信器から入力した各信号光の光パワーが同じであっ
ても、増幅された各信号光の光パワーは同一にならない
のが一般的である。特に光ファイバ増幅器の利得は信号
光の波長に大きく依存するので、利得のピーク近傍の波
長と利得のピークから離れた波長とでは最大１０ｄＢ程
度の出力パワーの差が生じる。In such an optical fiber amplifier for wavelength division multiplexing transmission, gain competition occurs between signal lights. For this reason,
Even if the optical power of each signal light input from the optical transmitter is the same, the amplified optical power of each signal light is generally not the same. In particular, since the gain of the optical fiber amplifier largely depends on the wavelength of the signal light, a maximum output power difference of about 10 dB occurs between the wavelength near the gain peak and the wavelength away from the gain peak.
【０００６】ところで、波長多重伝送用光ファイバ増幅
器では、光パワーのバラツキが大きくなると受信側にお
いてアイソレーション特性の劣化が起きる。すなわち、
受信側では多重化された信号光から元の各信号光を取り
出すのに光分波器を用いるが、一般的に光分波器には信
号光の間のクロストークがあり、他の信号光が雑音とし
て混入する。特に取り出そうとしている信号光の光パワ
ーが小さい場合には、クロストークによって混入した他
の大きな光パワーの信号光が相対的に大きな雑音となる
ため、受信感度の大幅な低下を招く。従って、このよう
な波長多重伝送用光ファイバ増幅器においては、増幅後
の各信号光の光パワーを同一レベルに揃えることが重要
である。By the way, in the optical fiber amplifier for WDM transmission, the isolation characteristic is deteriorated on the receiving side when the variation of the optical power becomes large. That is,
On the receiving side, an optical demultiplexer is used to extract each original signal light from the multiplexed signal light, but in general, the optical demultiplexer has crosstalk between signal lights and other signal lights. Is mixed in as noise. In particular, when the optical power of the signal light to be extracted is small, the signal light of the other large optical power mixed by the crosstalk becomes a relatively large noise, resulting in a significant decrease in the reception sensitivity. Therefore, in such an optical fiber amplifier for wavelength division multiplexing, it is important to equalize the optical power of each signal light after amplification to the same level.
【０００７】ところが、図２に示したような従来提案さ
れた波長多重伝送用光ファイバ増幅器では、各信号光ご
とに増幅率を制御することができない。そこで、光送信
器側で各信号光ごとに光パワーを調整することによっ
て、増幅後の各信号光の光パワーを揃える必要があっ
た。信号光の光パワーを調整する一般的な装置として、
特開昭６１−２８２４３には、電気光学効果を利用した
マッハ・ツェンダ型変調装置等が開示されている。However, in the conventionally proposed optical fiber amplifier for wavelength division multiplexing as shown in FIG. 2, the amplification factor cannot be controlled for each signal light. Therefore, it is necessary to adjust the optical power of each signal light on the optical transmitter side to make the optical power of each signal light after amplification uniform. As a general device to adjust the optical power of the signal light,
Japanese Patent Application Laid-Open No. 61-28243 discloses a Mach-Zehnder type modulator using the electro-optical effect.
【０００８】[0008]
【発明が解決しようとする課題】したがって、従来提案
された波長多重伝送用光ファイバ増幅器では、個々の信
号光の光出力パワーを所定の値に設定する作業が面倒で
あった。また、例えば波長多重伝送用光ファイバ増幅器
を構成する個々の部品の特性のバラツキ、温度変化、経
時変化によっても、各信号光に対して所期設定した光出
力パワーが変動するので、光送信器側の光パワーの調整
を繰り返し行わなければならないという不便さがあっ
た。Therefore, in the conventionally proposed optical fiber amplifier for wavelength division multiplex transmission, it is troublesome to set the optical output power of each signal light to a predetermined value. In addition, the optical output power set for each signal light also fluctuates due to variations in the characteristics of individual components constituting the optical fiber amplifier for wavelength division multiplexing transmission, changes in temperature, and changes with time. There was the inconvenience of having to repeatedly adjust the optical power on the side.
【０００９】そこで本発明の目的は、光送信器の光パワ
ーをいちいち調整しなくても、増幅器側で各信号光の光
出力パワーを所望のレベルに設定でき、しかも一旦設定
すればその出力パワーを維持することのできる波長多重
伝送用光ファイバ増幅器を提供することにある。Therefore, an object of the present invention is to set the optical output power of each signal light to a desired level on the amplifier side without adjusting the optical power of the optical transmitter one by one. An object of the present invention is to provide an optical fiber amplifier for wavelength division multiplexing transmission that can maintain the above.
【００１０】[0010]
【課題を解決するための手段】請求項１記載の発明で
は、相異なる波長の信号光を個別に入力する複数の信号
光入力手段と、各信号光を増幅するとともにこれらを多
重化する光増幅手段と、この光増幅手段での各信号光ご
との増幅率を可変にする増幅率可変手段と、光増幅手段
で増幅された各信号光がそれぞれ所定の出力レベルにな
るように増幅率可変手段を帰還制御する帰還制御手段と
を波長多重伝送用光ファイバ増幅器に具備させる。According to a first aspect of the present invention, a plurality of signal light input means for individually inputting signal lights of different wavelengths and an optical amplifier for amplifying each signal light and multiplexing them. Means, an amplification factor varying means for varying the amplification factor for each signal light in the optical amplifying means, and an amplification factor varying means for each signal light amplified by the optical amplification means to have a predetermined output level. And a feedback control means for feedback-controlling the optical fiber amplifier for wavelength division multiplexing.
【００１１】すなわち請求項１記載の発明では、相異な
る各信号光ごとの増幅率を可変にできる増幅率可変手段
に対して帰還制御を施すことにより、各信号光が所定の
出力レベルになるように増幅している。That is, according to the first aspect of the present invention, feedback control is performed on the amplification factor varying means capable of varying the amplification factor for each different signal light so that each signal light has a predetermined output level. Is amplified to.
【００１２】請求項２記載の発明では、相異なる波長の
信号光を個別に入力する複数の信号光入力手段と、各信
号光ごとの増幅率をそれぞれ可変にする増幅率可変手段
と、この増幅率可変手段の出力を合波する光合波器と、
この光合波器により合波された信号光を増幅する光増幅
器と、この光増幅器で増幅された信号光の一部を取り出
す光分岐器と、各信号光がそれぞれ所定の出力レベルに
なるように光分岐器で取り出された信号光を用いて増幅
率可変手段を帰還制御する帰還制御手段とを波長多重伝
送用光ファイバ増幅器に具備させる。According to the second aspect of the present invention, a plurality of signal light input means for individually inputting the signal light of different wavelengths, an amplification factor varying means for varying the amplification factor of each signal light, and this amplification are provided. An optical multiplexer that multiplexes the outputs of the rate varying means,
An optical amplifier that amplifies the signal light multiplexed by this optical multiplexer, an optical branching device that extracts a part of the signal light amplified by this optical amplifier, and an optical amplifier that makes each signal light a predetermined output level. An optical fiber amplifier for wavelength division multiplexing transmission is provided with feedback control means for feedback controlling the amplification factor varying means using the signal light extracted by the optical branching device.
【００１３】すなわち請求項２記載の発明では、相異な
る各信号光ごとの増幅率を可変にできる増幅率可変手段
に対して、光分岐器で取り出した増幅後の信号光の一部
を用いて帰還制御を施すことにより、各信号光が所定の
出力レベルになるように増幅している。That is, according to the second aspect of the invention, a part of the amplified signal light extracted by the optical branching device is used for the amplification factor varying means capable of varying the amplification factor for each different signal light. By performing feedback control, each signal light is amplified so as to have a predetermined output level.
【００１４】請求項３記載の発明では、相異なる波長の
信号光を個別に入力する複数の信号光入力手段と、各信
号光ごとの増幅率をそれぞれ可変にする光減衰器と、こ
の光減衰器の出力を合波する光合波器と、この光合波器
により合波された信号光を増幅する光増幅器と、この光
増幅器で増幅された信号光の一部を取り出す光分岐器
と、この光分岐器で取り出された信号光を各波長の信号
光に分波する光分波器と、この光分波器の出力をそれぞ
れ個別に電気信号に変換する光−電気変換器と、この光
−電気変換器の出力を用いて光増幅器で増幅された各信
号光がそれぞれ所定の出力レベルになるように光減衰器
を制御する減衰率制御手段とを波長多重伝送用光ファイ
バ増幅器に具備させる。According to a third aspect of the present invention, a plurality of signal light input means for individually inputting signal lights of different wavelengths, an optical attenuator for varying the amplification factor of each signal light, and this optical attenuation. Optical multiplexer that multiplexes the output of the optical device, an optical amplifier that amplifies the signal light that is multiplexed by this optical multiplexer, an optical branching device that extracts a part of the signal light that is amplified by this optical amplifier, and An optical demultiplexer that demultiplexes the signal light extracted by the optical branching device into signal light of each wavelength, an optical-electrical converter that individually converts the output of this optical demultiplexer into an electrical signal, and this optical An optical fiber amplifier for wavelength division multiplexing is provided with an attenuation factor control means for controlling the optical attenuator so that each signal light amplified by the optical amplifier using the output of the electrical converter has a predetermined output level. .
【００１５】すなわち請求項３記載の発明では、相異な
る各信号光ごとの増幅率を可変にできる光減衰器に対し
て、光分岐器と光分波器で取り出した増幅後の各信号光
を用いて帰還制御を施すことにより、各信号光が所定の
出力レベルになるように増幅している。That is, according to the third aspect of the present invention, the amplified signal lights extracted by the optical branching device and the optical demultiplexer are supplied to the optical attenuator capable of varying the amplification factor for each different signal light. By performing feedback control using the signal light, each signal light is amplified to a predetermined output level.
【００１６】[0016]
【実施例】以下実施例につき本発明を詳細に説明する。EXAMPLES The present invention will be described in detail below with reference to examples.
【００１７】図１は本発明の一実施例の波長多重伝送用
光ファイバ増幅器およびその周辺を表わしたものであ
る。光送信器３１1 〜３１n が送出する相異なる波長λ
1 〜λ n の各信号光は、本実施例の波長多重伝送用光フ
ァイバ増幅器３２に入力されるようになっている。波長
多重伝送用光ファイバ増幅器３２は、これらの信号光を
個別に入力する光減衰器３３1 〜３３n と、これらの光
減衰器３３1 〜３３n の出力を合波する光合波器（ＷＤ
Ｍ）３４を備えている。光合波器３４の出力はエルビウ
ム添加光ファイバ増幅器３５に入力される。エルビウム
添加光ファイバ増幅器３５の出力はこの波長多重伝送用
光ファイバ増幅器の出力として後段の図示しない光ファ
イバに入力される他、光分岐器３７に入力されて更に２
系統に分岐されるようになっている。FIG. 1 shows a wavelength division multiplex transmission according to an embodiment of the present invention.
Represents an optical fiber amplifier and its surroundings
It Optical transmitter 311~ 31nDifferent wavelengths emitted by
1~ Λ nThe respective signal lights of are the optical fibers for wavelength division multiplexing transmission of this embodiment.
It is adapted to be input to the fiber amplifier 32. wavelength
The optical fiber amplifier 32 for multiplex transmission transmits these signal lights.
Optical attenuator 33 input individually1~ 33nAnd these light
Attenuator 331~ 33nOptical multiplexer (WD
M) 34. The output of the optical multiplexer 34 is Erbiu
It is input to the optical fiber amplifier 35. erbium
The output of the doped optical fiber amplifier 35 is for this wavelength division multiplexing transmission.
As an output of the optical fiber amplifier, an optical fiber (not shown) at the latter stage is shown.
2 to the optical splitter 37,
It is designed to be branched into a system.
【００１８】このうちの最初の分岐出力は光−電気変換
器３８に入力されて電気信号に変換され、光ファイバ増
幅器３５に入力されて、前記したような利得制御に用い
られるようになっている。The first branch output of these is input to an optical-electrical converter 38, converted into an electric signal, and input to an optical fiber amplifier 35, which is used for the above-described gain control. .
【００１９】光分岐器３７によって分岐された他の出力
は、光分波器（ＷＤＭ）３９に入力され、前記した各波
長λ1 〜λn に分波される。光分波器３９から出力され
るこれら波長別の信号光は光−電気変換器４０1 〜４０
n に入力されてそれぞれ対応する電気信号に変換され
る。光−電気変換器４０1 〜４０n の出力は対応する減
衰率制御器４１1 〜４１n に入力され、予め設定されて
いる所定の出力レベルと個別に比較される。それらの結
果に基づいて、対応する第１〜第ｎの光減衰器３３1 〜
３３n の減衰率を変化させるようになっている。The other output split by the optical splitter 37 is input to the optical demultiplexer (WDM) 39 and split into the wavelengths λ 1 to λ n . The signal lights for each wavelength output from the optical demultiplexer 39 are opto-electric converters 40 1 to 40.
It is input to n and converted into corresponding electric signals. The outputs of the opto-electric converters 40 1 to 40 n are input to the corresponding attenuation rate controllers 41 1 to 41 n and individually compared with a preset predetermined output level. Based on those results, the corresponding optical attenuators 33 1 to the first to n
The attenuation factor of 33 n is changed.
【００２０】光減衰器３３1 〜３３n としては、印加電
圧によって光の透過率が変化する液晶が用いられてい
る。また、光合波器３４および光分波器３９は回折格子
を利用したものが用いられている。As the optical attenuators 33 1 to 33 n , liquid crystals whose light transmittance changes with applied voltage are used. Further, as the optical multiplexer 34 and the optical demultiplexer 39, those utilizing a diffraction grating are used.
【００２１】このような構成の波長多重伝送用光ファイ
バ増幅器の動作の説明を、簡単のためｎが“２”の場合
について行う。第１の光送信器３１1 から出力される波
長λ 1 の信号光（以後、第１の信号光と呼ぶ）と第２の
光送信器３１2 で発生した波長λ2 の信号光（以後、第
２の信号光と呼ぶ）は、波長多重伝送用光ファイバ増幅
器３２に入力され、対応する光減衰器３３1 〜３３n で
減衰される。第１の光減衰器３３1 と第２の光減衰器３
３2 はそれぞれ固有の減衰率を持っている。個々に減衰
された第１の信号光と第２の信号光は光合波器３４で多
重化され、後段のエルビウム添加光ファイバ増幅器３５
で所定の光出力パワーになるよう増幅される。An optical fiber for wavelength division multiplexing transmission having such a configuration
For the sake of simplicity of explanation of the operation of the amplifier, when n is "2"
Do about. First optical transmitter 311Wave output from
Long λ 1Signal light (hereinafter referred to as the first signal light) and the second signal light
Optical transmitter 312Wavelength λ generated at2Signal light (hereinafter,
2) is an optical fiber amplification for wavelength division multiplexing transmission.
To the corresponding optical attenuator 33.1~ 33nso
Attenuated. First optical attenuator 331And the second optical attenuator 3
Three2Have their own damping rates. Individually attenuated
The first signal light and the second signal light that have been separated are multiplexed by the optical multiplexer 34.
The erbium-doped optical fiber amplifier 35 that has been duplicated
It is amplified so as to have a predetermined optical output power.
【００２２】増幅された信号光は光分岐器３６を経て出
力されるが、その一部は光分岐器３７を経て光−電気変
換器３８に入力されて、エルビウム添加光ファイバ増幅
器３５を制御する。この帰還制御は波長多重伝送用光フ
ァイバ増幅器から出力される合波後の信号光を所定のレ
ベルに制御するための利得調整に使用される。The amplified signal light is output through the optical branching device 36, and a part thereof is input to the optical-electrical converter 38 through the optical branching device 37 to control the erbium-doped optical fiber amplifier 35. . This feedback control is used for gain adjustment for controlling the signal light after the multiplexing output from the optical fiber amplifier for wavelength division multiplexing to a predetermined level.
【００２３】一方、光分岐器３７から光分波器３９に到
達し、ここで分波された第１の信号光（波長λ1 ）と第
２の信号光（波長λ2 ）は、それぞれ対応する光−電気
変換器４０1 ，４０2 で電気信号に変換されて、同じく
対応する減衰率制御器４１1，４１2 に入力される。こ
れらの減衰率制御器４１1 ，４１2 では、信号光パワー
を表わす入力電気信号が所定のレベルに達しなければ対
応する光減衰器３３1または３３2 の減衰率が小さくな
るようにその印加電圧を制御し、逆に所定のレベルを越
えていれば対応する光減衰器の減衰率が大きくなるよう
にその印加電圧を制御する。これらの帰還制御は、先に
述べたエルビウム添加光ファイバ増幅器３５全体の利得
調整と異なり、各信号光ごとの利得調整を行うものであ
る。On the other hand, the first signal light (wavelength λ 1 ) and the second signal light (wavelength λ 2 ) that reach the optical demultiplexer 39 from the optical branching device 37 and are demultiplexed here correspond to each other. light - is converted into an electric signal in the electrical converter 40 1, 40 2 is inputted also to the corresponding damping rate controller 41 1, 41 2. In these attenuation rate controllers 41 1 and 41 2 , if the input electric signal representing the signal light power does not reach a predetermined level, the applied voltage so that the attenuation rate of the corresponding optical attenuator 33 1 or 33 2 becomes small. If the voltage exceeds a predetermined level, the applied voltage is controlled so that the attenuation factor of the corresponding optical attenuator increases. These feedback controls are different from the above-mentioned gain adjustment of the erbium-doped optical fiber amplifier 35 as a whole and are for gain adjustment for each signal light.
【００２４】このように各信号光ごとの利得制御を行う
ことにより、第１および第２の信号光を、所望の光出力
パワーになるように増幅することができる。ここでは説
明上の都合により、ｎが“２”の場合について説明を行
ったが、ｎが“３”以上の場合、すなわち信号光が３個
以上の場合にも全く同様に動作することは言うまでもな
い。By thus controlling the gain for each signal light, the first and second signal lights can be amplified to have a desired optical output power. Here, for convenience of explanation, the case where n is “2” has been described, but it goes without saying that the same operation is performed when n is “3” or more, that is, when there are three or more signal lights. Yes.
【００２５】また、本実施例では光出力パワー設定の自
由度を大きくするためにエルビウム添加光ファイバ増幅
器３５に対して帰還制御を行っているが、各信号光ごと
の利得を制御しているのは光減衰器３３1 〜３３n であ
るから、この帰還制御がなくても各信号光ごとの光出力
パワーを揃えられることには変わりがない。In the present embodiment, feedback control is performed on the erbium-doped optical fiber amplifier 35 in order to increase the degree of freedom in setting the optical output power, but the gain for each signal light is controlled. no is because an optical attenuator 33 1 ~33 n, remains that the aligned optical output power of each signal light even without the feedback control.
【００２６】さらに、増幅率可変手段として、印加電圧
により透過率の変化する液晶の代わりに別のタイプの光
減衰器を使用してもよい。また、本実施例ではコストが
安いことと設置スペースが少なくてすむことを考慮して
光減衰器を用いているが、光増幅器を用いても差し支え
ない。Further, as the amplification factor varying means, another type of optical attenuator may be used instead of the liquid crystal whose transmittance changes depending on the applied voltage. Further, in this embodiment, the optical attenuator is used in consideration of the low cost and the small installation space, but an optical amplifier may be used.
【００２７】[0027]
【発明の効果】以上説明したように請求項１記載の発明
によれば、相異なる波長の各信号光に対して個別に増幅
率を変化させることができ、光送信器側でいちいち光パ
ワーの調整を行わなくても、光増幅器側で各信号光の光
出力パワーを容易に所定のレベルに設定できる。また、
この光出力レベルを一旦設定すれば、波長多重伝送用光
ファイバ増幅器を構成する部品の特性が温度変化や経時
変化によって変動しても、初期設定された光出力パワー
を維持するよう自動的に各信号光ごとの増幅率が補正制
御されるという効果もある。As described above, according to the invention described in claim 1, the amplification factor can be changed individually for each signal light having a different wavelength, and the optical power of the optical transmitter can be changed one by one. The optical output power of each signal light can be easily set to a predetermined level on the optical amplifier side without any adjustment. Also,
Once this optical output level is set, even if the characteristics of the components that make up the optical fiber amplifier for WDM transmission fluctuate due to changes in temperature and changes over time, each optical output power is automatically maintained to maintain the initial set optical output power. There is also an effect that the amplification factor for each signal light is corrected and controlled.
【００２８】また請求項２記載の発明によれば、多重化
された信号光全体の利得調整と各波長ごとの利得調整を
互いに独立して行なえるようにしたので、利得調整が容
易になるという効果がある。According to the second aspect of the invention, since the gain adjustment of the entire multiplexed signal light and the gain adjustment for each wavelength can be performed independently of each other, the gain adjustment can be facilitated. effective.
【００２９】さらに請求項３記載の発明によれば、光増
幅器と比べてコストが安く設置スペースの面でも有利な
光減衰器を用いているので、波長多重伝送用光ファイバ
増幅器の低コスト化およびコンパクト化を図ることがで
きる。Further, according to the third aspect of the invention, since the optical attenuator is used, which is lower in cost than the optical amplifier and advantageous in terms of installation space, the cost of the optical fiber amplifier for wavelength division multiplex transmission can be reduced and It can be made compact.
【図１】本発明の一実施例における波長多重伝送用光フ
ァイバ増幅器およびその周辺の構成を表わした概略説明
図である。FIG. 1 is a schematic explanatory diagram showing a configuration of an optical fiber amplifier for wavelength division multiplexing transmission and its periphery in an embodiment of the present invention.
【図２】従来の波長多重伝送用光ファイバ増幅器および
その周辺の構成を表わした概略説明図である。FIG. 2 is a schematic explanatory view showing a configuration of a conventional optical fiber amplifier for wavelength division multiplexing transmission and its periphery.
１１k 第ｋの光送信器（１≦ｋ≦ｎ） １２ 従来の波長多重伝送用光ファイバ増幅器 １３ 光合波器（ＷＤＭ） １４ エルビウム添加光ファイバ増幅器 １５ 光分岐器 １６ 光−電気変換器 ３１k 第ｋの光送信器（１≦ｋ≦ｎ） ３２ 本発明の波長多重伝送用光ファイバ増幅器 ３３k 第ｋの光減衰器（１≦ｋ≦ｎ） ３４ 光合波器（ＷＤＭ） ３５ エルビウム添加光ファイバ増幅器 ３６，３７ 光分岐器 ３８ 第（ｎ＋１）の光−電気変換器 ３９ 光分波器（ＷＤＭ） ４０k 第ｋの光−電気変換器（１≦ｋ≦ｎ） ４１k 第ｋの減衰率制御器（１≦ｋ≦ｎ）11 k- th optical transmitter (1 ≦ k ≦ n) 12 Conventional optical fiber amplifier for wavelength division multiplexing 13 Optical multiplexer (WDM) 14 Erbium-doped optical fiber amplifier 15 Optical brancher 16 Optical-electrical converter 31 k Kth optical transmitter (1 ≦ k ≦ n) 32 optical fiber amplifier for wavelength division multiplexing transmission of the present invention 33 k kth optical attenuator (1 ≦ k ≦ n) 34 optical multiplexer (WDM) 35 erbium-doped light Fiber amplifier 36, 37 Optical brancher 38 (n + 1) th optical-electrical converter 39 Optical demultiplexer (WDM) 40 kth optical-electrical converter (1 ≦ k ≦ n) 41 kth attenuation Rate controller (1 ≦ k ≦ n)
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｈ０４Ｂ 10/14 10/06 10/04 ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification code Internal reference number FI technical display location H04B 10/14 10/06 10/04
Claims (3)
複数の信号光入力手段と、 前記各信号光を増幅するとともにこれらを多重化する光
増幅手段と、 この光増幅手段での前記各信号光ごとの増幅率を可変に
する増幅率可変手段と、 前記光増幅手段で増幅された前記各信号光がそれぞれ所
定の出力レベルになるように前記増幅率可変手段を帰還
制御する帰還制御手段とを具備することを特徴とする波
長多重伝送用光ファイバ増幅器。1. A plurality of signal light inputting means for individually inputting signal light of different wavelengths, an optical amplifying means for amplifying the signal light and multiplexing them, and each of the optical amplifying means. Amplification factor varying means for varying the amplification factor for each signal light, and feedback control means for feedback controlling the amplification factor varying means so that each of the signal lights amplified by the optical amplifying device has a predetermined output level. An optical fiber amplifier for wavelength division multiplex transmission, comprising:
複数の信号光入力手段と、 前記各信号光ごとの増幅率をそれぞれ可変にする増幅率
可変手段と、 この増幅率可変手段の出力を合波する光合波器と、 この光合波器により合波された信号光を増幅する光増幅
器と、 この光増幅器で増幅された信号光の一部を取り出す光分
岐器と、 前記各信号光がそれぞれ所定の出力レベルになるように
前記光分岐器で取り出された信号光を用いて前記増幅率
可変手段を帰還制御する帰還制御手段とを具備すること
を特徴とする波長多重伝送用光ファイバ増幅器。2. A plurality of signal light inputting means for individually inputting signal light of different wavelengths, an amplification factor varying means for varying an amplification factor for each signal light, and an output of the amplification factor varying means. An optical multiplexer that multiplexes the optical signal, an optical amplifier that amplifies the signal light multiplexed by the optical multiplexer, an optical branching device that extracts a part of the signal light amplified by the optical amplifier, and each of the signal light And a feedback control means for feedback-controlling the amplification factor varying means by using the signal light extracted by the optical branching device so that each becomes a predetermined output level. amplifier.
複数の信号光入力手段と、 前記各信号光ごとの増幅率をそれぞれ可変にする光減衰
器と、 この増幅率可変手段の出力を合波する光合波器と、 この光合波器により合波された信号光を増幅する光増幅
器と、 この光増幅器で増幅された信号光の一部を取り出す光分
岐器と、 この光分岐器で取り出された信号光を前記各波長の信号
光に分波する光分波器と、 この光分波器の出力をそれぞれ個別に電気信号に変換す
る光−電気変換器と、 この光−電気変換器の出力を用いて前記光増幅器で増幅
された前記各信号光がそれぞれ所定の出力レベルになる
ように前記光減衰器を制御する減衰率制御手段とを具備
することを特徴とする波長多重伝送用光ファイバ増幅
器。3. A plurality of signal light input means for individually inputting signal lights of different wavelengths, an optical attenuator for varying the amplification factor of each of the signal lights, and an output of the amplification factor varying means. An optical multiplexer for multiplexing, an optical amplifier for amplifying the signal light combined by this optical multiplexer, an optical branching device for extracting a part of the signal light amplified by this optical amplifier, and this optical branching device An optical demultiplexer that demultiplexes the extracted signal light into signal light of each wavelength, an optical-electrical converter that individually converts the output of the optical demultiplexer into an electrical signal, and an optical-electrical conversion Wavelength-division multiplex transmission, which comprises an attenuation factor control means for controlling the optical attenuator so that each of the signal lights amplified by the optical amplifier has a predetermined output level by using the output of the optical amplifier. Optical fiber amplifier.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5171342A JP2826444B2 (en) | 1993-07-12 | 1993-07-12 | Optical fiber amplifier for WDM transmission |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5171342A JP2826444B2 (en) | 1993-07-12 | 1993-07-12 | Optical fiber amplifier for WDM transmission |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0730520A true JPH0730520A (en) | 1995-01-31 |
| JP2826444B2 JP2826444B2 (en) | 1998-11-18 |
Family
ID=15921442
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5171342A Expired - Lifetime JP2826444B2 (en) | 1993-07-12 | 1993-07-12 | Optical fiber amplifier for WDM transmission |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2826444B2 (en) |
Cited By (22)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2737827A1 (en) * | 1995-08-08 | 1997-02-14 | Nec Corp | WAVELENGTH DIVISION MULTIPLEXING TRANSMISSION SYSTEM |
| FR2740282A1 (en) * | 1995-10-19 | 1997-04-25 | Nec Corp | APPARATUS FOR MEASURING OPTICAL TRANSMISSION LINE PROPERTY AND OPTICAL WAVELENGTH MULTIPLEXING TRANSMISSION APPARATUS |
| EP0734129A3 (en) * | 1995-03-20 | 1997-05-07 | Fujitsu Ltd | Optical amplification device for several waves |
| DE19547603A1 (en) * | 1995-12-20 | 1997-06-26 | Sel Alcatel Ag | Optical amplifier device |
| US5986800A (en) * | 1995-04-05 | 1999-11-16 | Hitachi, Ltd. | Optical amplification apparatus |
| US6031659A (en) * | 1996-05-31 | 2000-02-29 | Fujitsu Limited | Optical amplifier for wavelength-division multiplexing |
| US6031644A (en) * | 1996-11-25 | 2000-02-29 | Fujitsu Limited | Method, device, and system for controlling wavelength of optical signal |
| WO2000057590A1 (en) * | 1999-03-22 | 2000-09-28 | Ciena Corporation | Dense wdm optical multiplexer and demultiplexer |
| US6134034A (en) * | 1996-03-18 | 2000-10-17 | Fujitsu Limited | Apparatus and method for controlling power levels of individual signal lights of a wavelength division multiplexed signal light |
| WO2001015291A1 (en) * | 1999-08-23 | 2001-03-01 | Fujitsu Limited | Wavelength multiplexer |
| JP2002044019A (en) * | 2000-05-18 | 2002-02-08 | Marconi Communications Ltd | Radiated power equalizer |
| WO2002089379A1 (en) * | 2001-04-26 | 2002-11-07 | Bookham Technology Plc | Integrated optical waveguide device |
| JP2003060574A (en) * | 2001-08-20 | 2003-02-28 | Hitachi Ltd | Optical transmission system, wavelength multiplexer, and dispersion compensation method for wavelength multiplex transmission system |
| WO2002075380A3 (en) * | 2001-03-19 | 2003-05-22 | Bookham Technology Plc | Optical channel monitor |
| US6577652B1 (en) | 1998-06-12 | 2003-06-10 | Nec Corporation | Optical add-drop multiplexer of WDM optical signals |
| US6594046B1 (en) | 1998-05-11 | 2003-07-15 | Nec Corporation | Level-flattening circuit for WDM optical signals |
| US6839518B1 (en) | 1999-12-24 | 2005-01-04 | Fujitsu Limited | Level adjustment method and wavelength division multiplexing device and system |
| JP2005269007A (en) * | 2004-03-17 | 2005-09-29 | Fujitsu Ltd | Terminal station apparatus, optical output power control method, and optical output power control program |
| US7336906B2 (en) | 2001-10-09 | 2008-02-26 | Ericsson Ab | Optical signal transmission |
| JP2008211838A (en) * | 1998-02-27 | 2008-09-11 | Fujitsu Ltd | Wavelength demultiplexer and optical repeater |
| US8064771B2 (en) | 2005-06-30 | 2011-11-22 | Infinera Corporation | Active control loop for power control of optical channel groups |
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|---|---|---|---|---|
| EP0734129A3 (en) * | 1995-03-20 | 1997-05-07 | Fujitsu Ltd | Optical amplification device for several waves |
| US5870217A (en) * | 1995-03-20 | 1999-02-09 | Fujitsu Limited | Multi-wavelength optical batch amplification apparatus |
| US6094296A (en) * | 1995-04-05 | 2000-07-25 | Hitachi, Ltd. | Optical amplification apparatus |
| US6373622B1 (en) | 1995-04-05 | 2002-04-16 | Hitachi, Ltd. | Optical amplification apparatus |
| US5986800A (en) * | 1995-04-05 | 1999-11-16 | Hitachi, Ltd. | Optical amplification apparatus |
| US6525871B2 (en) | 1995-04-05 | 2003-02-25 | Hitachi, Ltd. | Optical amplification apparatus |
| US6839161B2 (en) | 1995-04-05 | 2005-01-04 | Hitachi, Ltd. | Optical amplification apparatus |
| US6256141B1 (en) | 1995-04-05 | 2001-07-03 | Hitachi, Ltd. | Optical amplification apparatus |
| FR2737827A1 (en) * | 1995-08-08 | 1997-02-14 | Nec Corp | WAVELENGTH DIVISION MULTIPLEXING TRANSMISSION SYSTEM |
| FR2740282A1 (en) * | 1995-10-19 | 1997-04-25 | Nec Corp | APPARATUS FOR MEASURING OPTICAL TRANSMISSION LINE PROPERTY AND OPTICAL WAVELENGTH MULTIPLEXING TRANSMISSION APPARATUS |
| DE19547603A1 (en) * | 1995-12-20 | 1997-06-26 | Sel Alcatel Ag | Optical amplifier device |
| US6134034A (en) * | 1996-03-18 | 2000-10-17 | Fujitsu Limited | Apparatus and method for controlling power levels of individual signal lights of a wavelength division multiplexed signal light |
| US6271945B1 (en) | 1996-03-18 | 2001-08-07 | Fujitsu Limited | Apparatus and method for controlling power levels of individual signal lights of a wavelength division multiplexed signal light |
| US6031659A (en) * | 1996-05-31 | 2000-02-29 | Fujitsu Limited | Optical amplifier for wavelength-division multiplexing |
| US6031644A (en) * | 1996-11-25 | 2000-02-29 | Fujitsu Limited | Method, device, and system for controlling wavelength of optical signal |
| JP2008211838A (en) * | 1998-02-27 | 2008-09-11 | Fujitsu Ltd | Wavelength demultiplexer and optical repeater |
| JP4485581B2 (en) * | 1998-02-27 | 2010-06-23 | 富士通株式会社 | Wavelength demultiplexer and optical repeater |
| US6594046B1 (en) | 1998-05-11 | 2003-07-15 | Nec Corporation | Level-flattening circuit for WDM optical signals |
| US6577652B1 (en) | 1998-06-12 | 2003-06-10 | Nec Corporation | Optical add-drop multiplexer of WDM optical signals |
| WO2000057590A1 (en) * | 1999-03-22 | 2000-09-28 | Ciena Corporation | Dense wdm optical multiplexer and demultiplexer |
| US6567196B1 (en) | 1999-03-22 | 2003-05-20 | Ciena Corporation | Dense WDM optical multiplexer and demultiplexer |
| EP1211763A4 (en) * | 1999-08-23 | 2007-12-05 | Fujitsu Ltd | WAVELENGTH MULTIPLEXER |
| EP1962394A2 (en) * | 1999-08-23 | 2008-08-27 | Fujitsu Limited | Wavelength division multiplexing apparatus |
| WO2001015291A1 (en) * | 1999-08-23 | 2001-03-01 | Fujitsu Limited | Wavelength multiplexer |
| US6707963B2 (en) | 1999-08-23 | 2004-03-16 | Fujitsu Limited | Wavelength division multiplexing apparatus |
| EP1211763A1 (en) * | 1999-08-23 | 2002-06-05 | Fujitsu Limited | Wavelength multiplexer |
| EP1962394A3 (en) * | 1999-08-23 | 2008-09-17 | Fujitsu Limited | Wavelength division multiplexing apparatus |
| US6839518B1 (en) | 1999-12-24 | 2005-01-04 | Fujitsu Limited | Level adjustment method and wavelength division multiplexing device and system |
| JP2002044019A (en) * | 2000-05-18 | 2002-02-08 | Marconi Communications Ltd | Radiated power equalizer |
| JP2011151832A (en) * | 2000-05-18 | 2011-08-04 | Ericsson Ab | Radiation power equalizer |
| JP2013017209A (en) * | 2000-05-18 | 2013-01-24 | Ericsson Ab | Radiation power equalizer |
| WO2002075380A3 (en) * | 2001-03-19 | 2003-05-22 | Bookham Technology Plc | Optical channel monitor |
| WO2002089379A1 (en) * | 2001-04-26 | 2002-11-07 | Bookham Technology Plc | Integrated optical waveguide device |
| JP2003060574A (en) * | 2001-08-20 | 2003-02-28 | Hitachi Ltd | Optical transmission system, wavelength multiplexer, and dispersion compensation method for wavelength multiplex transmission system |
| JP4741118B2 (en) * | 2001-08-20 | 2011-08-03 | 株式会社日立製作所 | Optical transmission system, wavelength division multiplexer, and dispersion compensation method for wavelength division multiplexing transmission system |
| US7336906B2 (en) | 2001-10-09 | 2008-02-26 | Ericsson Ab | Optical signal transmission |
| JP2005269007A (en) * | 2004-03-17 | 2005-09-29 | Fujitsu Ltd | Terminal station apparatus, optical output power control method, and optical output power control program |
| US8064771B2 (en) | 2005-06-30 | 2011-11-22 | Infinera Corporation | Active control loop for power control of optical channel groups |
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