JPH11135862A - Optical amplifier - Google Patents

Optical amplifier

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Publication number
JPH11135862A
JPH11135862A JP29402997A JP29402997A JPH11135862A JP H11135862 A JPH11135862 A JP H11135862A JP 29402997 A JP29402997 A JP 29402997A JP 29402997 A JP29402997 A JP 29402997A JP H11135862 A JPH11135862 A JP H11135862A
Authority
JP
Japan
Prior art keywords
optical
wavelength
signal
optical signal
optical signals
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
Application number
JP29402997A
Other languages
Japanese (ja)
Inventor
Keiichi Kitamura
圭一 北村
Toru Kazawa
徹 加沢
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP29402997A priority Critical patent/JPH11135862A/en
Publication of JPH11135862A publication Critical patent/JPH11135862A/en
Pending legal-status Critical Current

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Abstract

PROBLEM TO BE SOLVED: To reduce amount of surge light produced by dividing inputted optical signals into two parts and performing logical code inversion and waveform conversion on one part and coupling and amplification to the other part, and then extracting only the wavelength component of the optical signals, so that the coupled optical signals become optical signals having a fixed power level. SOLUTION: Optical signals having a wavelength 1 and inputted to an input terminal 101 are divided into two by means of an optical distributor 211, and one part is inputted to an optical coupler 207. The other part is made incident to an optical receiver 203, is converted into electrical signals of the level corresponding to the power, inverts logical codes by means of an inverting amplifier 2051, and is made into the drive signal of a light source 206. The light source 206 outputs optical signals having a wavelength λ2 in accordance with the drive signal. After the optical signals having the wavelength λ2 are divided into two parts by means of the optical distributor 211 and coupled with the other part of the optical signals having the wavelength λ1 by means of an optical coupler 207, the coupled signals are made incident to an optical fiber amplifier 202 for amplification. A wavelength pass filter 209 only extracts the component having the wavelength #11 from the (coupled) light and outputs the component to the outside. When the optical signals inputted to the optical fiber amplifier is constant, the amount of surge light produced can be reduced.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は、光ファイバ増幅器
を用いた通信用の光増幅装置に係り、特に、断続的に通
信される光信号の増幅に用いることに好適な光増幅装置
に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical amplifying device for communication using an optical fiber amplifier, and more particularly to an optical amplifying device suitable for amplifying an intermittently communicated optical signal.

【0002】[0002]

【従来の技術】幹線系光伝送システム等において広帯域
の光信号の中継を行なう光中継器には、光ファイバ増幅
器(例えばエルビウムドープファイバ)および半導体光
増幅回路により光信号を直接増幅する光増幅装置が用い
られる。ただし、この光ファイバ増幅器は、光信号入力
開始時にサージ光が発生することや、入力光の電力に応
じて増幅利得が変化すること等、増幅器として好ましく
ない特徴を有する。
2. Description of the Related Art An optical repeater for relaying a broadband optical signal in a trunk optical transmission system or the like includes an optical amplifier for directly amplifying an optical signal by an optical fiber amplifier (for example, erbium-doped fiber) and a semiconductor optical amplifier circuit. Is used. However, this optical fiber amplifier has unfavorable characteristics as an amplifier, such as generation of surge light at the start of inputting an optical signal, and a change in amplification gain depending on the power of input light.

【0003】このような特徴を考慮して良好な増幅特性
を得るようにした従来の光増幅装置の構成としては、図
3に示すもの(1996年電子情報通信学会総合大会、B-11
90「EDFAの光サージ抑圧方法に関する一検討」参照)が
知られている。
FIG. 3 shows a configuration of a conventional optical amplifying device that obtains good amplification characteristics in consideration of such characteristics (1996 IEICE General Conference, B-11).
90 "A Study on Optical Surge Suppression Method for EDFA") is known.

【0004】図3に示す光増幅装置は、入力された波長
λ1の信号光を、光合波器207、光ファイバ増幅器2
02、通過波長フィルタ209を介して出力する。光合
波器207では、波長λ1の信号光に、高電力の波長λ
2のバイアス光を合成する。そして、通過波長フィルタ
209では、波長λ1の信号光のみを抽出し、出力す
る。この方式では、高電力のバイアス光を光ファイバ増
幅器202に常時入射させることで、光ファイバ増幅器
202内での励起キャリアの蓄積を防止し、サージ光の
抑圧と、利得の安定化とを図っている。
The optical amplifier shown in FIG. 3 converts an input signal light of wavelength λ1 into an optical multiplexer 207 and an optical fiber amplifier 2.
02, output through the pass wavelength filter 209. In the optical multiplexer 207, the signal light having the wavelength λ1 is added to the high power wavelength λ.
The second bias light is synthesized. Then, the pass wavelength filter 209 extracts and outputs only the signal light of the wavelength λ1. In this method, high-power bias light is always incident on the optical fiber amplifier 202 to prevent accumulation of pump carriers in the optical fiber amplifier 202, thereby suppressing surge light and stabilizing the gain. I have.

【0005】[0005]

【発明が解決しようとする課題】上記従来の光増幅装置
では、出力光のサージ光を抑制するために、増幅対象の
波長λ1の光信号に対し、波長λ2のバイアス光の電力
を高くする必要がある。しかし、光ファイバ増幅器は、
入力光の電力の増加に伴い、増幅利得が減少するという
特性があるため、波長λ2のバイアス光の電力を十分に
高くすることはできない。つまり、波長λ1の光信号が
断続的に入力される場合、この光増幅装置では、サージ
光の発生および利得変動を完全に抑圧することはできな
い。
In the above-mentioned conventional optical amplifier, in order to suppress the surge light of the output light, it is necessary to increase the power of the bias light of the wavelength λ2 with respect to the optical signal of the wavelength λ1 to be amplified. There is. However, optical fiber amplifiers
Since there is a characteristic that the amplification gain decreases with an increase in the power of the input light, the power of the bias light having the wavelength λ2 cannot be sufficiently increased. That is, when the optical signal of the wavelength λ1 is intermittently input, this optical amplifying device cannot completely suppress the generation of the surge light and the gain fluctuation.

【0006】本発明の目的は、断続的に入力される光信
号を増幅する際の、サージ光の発生量および光増幅利得
の変動をより低減することが可能な光増幅装置を提供す
ることにある。
SUMMARY OF THE INVENTION It is an object of the present invention to provide an optical amplifying device capable of further reducing the amount of generation of surge light and fluctuations in optical amplification gain when amplifying an optical signal intermittently input. is there.

【0007】[0007]

【課題を解決するための手段】上記課題を解決するた
め、本発明は、入力された光信号を2つに分配する光分
配器と、該光分配器の一方の分配出力の光信号に対し、
論理符号反転および波長変更の操作を行なう符号反転部
と、該符号反転部で処理された光信号、および、前記光
分配器の他方の分配出力の光信号を合成する光合波器
と、合成された光信号を増幅する光増幅器と、増幅され
た光信号から、前記光分配器に入力される光信号の波長
の成分のみを抽出する通過波長フィルタとを備え、前記
光合波器で合成された光信号が一定の電力レベルの光信
号となることを特徴とする光増幅装置を提供する。
SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides an optical splitter for splitting an input optical signal into two, and an optical splitter for splitting an optical signal at one output of the optical splitter. ,
A sign inverting unit for performing operations of logical sign inversion and wavelength change, an optical signal processed by the sign inverting unit, and an optical multiplexer for combining the optical signal of the other distribution output of the optical distributor; An optical amplifier for amplifying the optical signal, and a pass wavelength filter for extracting only the wavelength component of the optical signal input to the optical distributor from the amplified optical signal, Provided is an optical amplifier, wherein the optical signal is an optical signal having a constant power level.

【0008】[0008]

【発明の実施の形態】以下、本発明の実施形態に係る光
増幅装置について、図面を用いて説明する。
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An optical amplifier according to an embodiment of the present invention will be described below with reference to the drawings.

【0009】光ファイバ増幅器の出力に現れるサージ光
は、光ファイバ増幅器で入力なしの状態が続いた後、高
電力の光信号が入力され始めた時に発生する。つまり、
光ファイバ増幅器に入力される光信号の電力が一定の場
合にはサージ光は発生しない。この特徴を利用して、本
実施形態の光増幅装置は、増幅対象の光信号が断続的に
入射される場合にも、その光信号を均一の利得で光増幅
できるようにしている。
[0009] Surge light appearing at the output of the optical fiber amplifier is generated when a high power optical signal starts to be input after the state where no input is continued in the optical fiber amplifier. That is,
When the power of the optical signal input to the optical fiber amplifier is constant, no surge light is generated. Utilizing this feature, the optical amplifying device of the present embodiment is capable of amplifying the optical signal with a uniform gain even when the optical signal to be amplified is intermittently incident.

【0010】図1に、本実施形態の光増幅装置の構成例
を示す。
FIG. 1 shows a configuration example of an optical amplifying device according to the present embodiment.

【0011】図示する光増幅装置は、光分配器211、
光合波器207、光ファイバ増幅器202、波長λ1の
通過波長フィルタ209、光受信器203、反転増幅器
2051、および、波長λ2の光源208により構成さ
れている。なお、光ファイバ増幅器202は、波長λ1
および波長λ2について、同じ利得を持つものである。
The illustrated optical amplifying device comprises an optical distributor 211,
It comprises an optical multiplexer 207, an optical fiber amplifier 202, a pass wavelength filter 209 of wavelength λ1, an optical receiver 203, an inverting amplifier 2051, and a light source 208 of wavelength λ2. The optical fiber amplifier 202 has a wavelength λ1
And the same gain for the wavelength λ2.

【0012】入力端子101に入力された波長λ1の光
信号は、光分配器211で2つに分岐され、一方は光合
波器207、他方は光受信器203に入射される。光受
信器203の入射光は、その電力に応じたレベルの電気
信号に変換され、反転増幅器2051で論理符号を反転
されて、光源206の駆動信号となる。光源206はこ
の駆動信号に従い波長λ2の光信号を出力する。この出
力光(波長λ2)は、光分配器211で分岐されたもう
一方の光信号(波長λ1)と、光合波器207で合成さ
れた後、光ファイバ増幅器202に入射され、増幅され
る。そして、増幅された合成光は、通過波長フィルタ2
09で波長λ1の成分のみを抽出され、外部に出力され
る。
The optical signal of wavelength λ1 input to the input terminal 101 is split into two by an optical splitter 211, one of which is input to an optical multiplexer 207 and the other is input to an optical receiver 203. The incident light of the optical receiver 203 is converted into an electric signal of a level according to the power, and the logical sign is inverted by the inverting amplifier 2051 to become a drive signal of the light source 206. The light source 206 outputs an optical signal having the wavelength λ2 according to the driving signal. The output light (wavelength λ2) is combined with the other optical signal (wavelength λ1) branched by the optical splitter 211 by the optical multiplexer 207, and then input to the optical fiber amplifier 202 and amplified. Then, the amplified combined light is passed through the passing wavelength filter 2.
At 09, only the component of the wavelength λ1 is extracted and output to the outside.

【0013】図2に、光ファイバ増幅器202に入力さ
れる光信号を示す。図中、光信号701および702は
光分配器211の分配出力であり、光信号701は光合
波器207に入力される波長λ1の信号成分、光信号7
02は光合波器207に入力される波長λ2の信号成
分、光信号703は、光信号701および702の合成
により得られる光ファイバ増幅器202の入力光であ
る。
FIG. 2 shows an optical signal input to the optical fiber amplifier 202. In the figure, optical signals 701 and 702 are distribution outputs of the optical distributor 211, and the optical signal 701 is a signal component of the wavelength λ1 input to the optical multiplexer 207,
Reference numeral 02 denotes a signal component of the wavelength λ2 input to the optical multiplexer 207, and an optical signal 703 is input light of the optical fiber amplifier 202 obtained by combining the optical signals 701 and 702.

【0014】図示のように、波長λ2の光信号702
は、波長λ1の光信号701の光のオン/オフ状態(論
理符号)を反転した光信号である。つまり、波長λ1の
光信号701がオン状態(論理符号が”1”)の期間、
波長λ2の光信号702はオフ状態(論理符号が”
0”)となり、波長λ1の光信号701がオフ状態の期
間、波長λ2の光信号702はオン状態になる。また、
波長λ2の光信号702は、電力が波長λ1の光信号7
01と同じとなるように生成される。波長λ2の光信号
702をこのように生成することで、波長λ1の光信号
701が断続的に入力される場合にも、光ファイバ増幅
器202に入力される光信号703の電力が常に一定レ
ベルPに保たれる。
As shown, an optical signal 702 of wavelength λ2
Is an optical signal obtained by inverting the on / off state (logical sign) of the light of the optical signal 701 having the wavelength λ1. That is, while the optical signal 701 of the wavelength λ1 is in the ON state (the logical code is “1”),
The optical signal 702 of the wavelength λ2 is in the OFF state (the logical code is “
0 ″), and while the optical signal 701 of the wavelength λ1 is in the off state, the optical signal 702 of the wavelength λ2 is in the on state.
The optical signal 702 having the wavelength λ2 is the optical signal 7 having the power of the wavelength λ1.
It is generated to be the same as 01. By generating the optical signal 702 of the wavelength λ2 in this manner, even when the optical signal 701 of the wavelength λ1 is intermittently input, the power of the optical signal 703 input to the optical fiber amplifier 202 is always at a constant level P. Is kept.

【0015】また、本実施形態の光増幅装置では、波長
λ1の光信号701のオン時における電力が変動するよ
うな場合にも、安定した利得を得ることができる。波長
λ1の光信号701のオン時の電力Pが最大値Pmax
〜最小値Pminの範囲で変化するような場合、波長λ
2の光信号702は、オン時の電力がPmax、オフ時
の電力が[Pmax−P]となるように生成される。こ
れにより、合成した光信号703の電力は常にPmax
一定となる。このように、波長λ1の光信号701の電
力が変動した場合にも、合成した信号光703の電力が
一定となるため、光増幅器は一定の増幅利得で、安定し
た光増幅を行うことができる。
Further, in the optical amplifying apparatus according to the present embodiment, a stable gain can be obtained even when the power of the optical signal 701 having the wavelength λ1 at the time of ON changes. The power P when the optical signal 701 of the wavelength λ1 is turned on is the maximum value Pmax.
, The wavelength λ
The second optical signal 702 is generated such that the power when on is Pmax and the power when off is [Pmax-P]. Thus, the power of the combined optical signal 703 is always Pmax
It will be constant. As described above, even when the power of the optical signal 701 of the wavelength λ1 fluctuates, the power of the combined signal light 703 is constant, so that the optical amplifier can perform stable optical amplification with a constant amplification gain. .

【0016】[0016]

【発明の効果】以上で説明したように、本発明によれ
ば、断続的に入力される光信号を増幅する際の、サージ
光の発生量および光増幅利得の変動をより低減すること
が可能な光増幅装置を提供することができる。
As described above, according to the present invention, it is possible to further reduce the amount of generation of surge light and fluctuations in optical amplification gain when amplifying an optical signal input intermittently. A simple optical amplifier can be provided.

【図面の簡単な説明】[Brief description of the drawings]

【図1】 本発明による光増幅装置の実施形態である。FIG. 1 is an embodiment of an optical amplifying device according to the present invention.

【図2】 図1に示す光増幅装置の動作を説明するため
の図である。
FIG. 2 is a diagram for explaining the operation of the optical amplifying device shown in FIG.

【図3】 従来の光増幅装置を示す接続図である。FIG. 3 is a connection diagram showing a conventional optical amplifier.

【符号の説明】[Explanation of symbols]

101:入力端子 102:出力端子 202:光ファイバ増幅器 203:光受信器 2051:反転増幅器 207:光合波器 208:波長λ2の光源 209:通過波長フィルタ 211:光分配器 607:時間軸 608:光電力の軸 701:波長λ1の光信号 702:波長λ2の光信号 703:波長λ1の光701と波長λ2の光702を合成した光信
号 706:波長λ1の光信号701および波長λ2の光信号702の
ピーク電力P 707:波長λ1の光信号701と波長λ2の光信号702を合成
した直流の光電力P 708:光オンの状態 709:光オフの状態
101: input terminal 102: output terminal 202: optical fiber amplifier 203: optical receiver 2051: inverting amplifier 207: optical multiplexer 208: light source of wavelength λ2 209: pass wavelength filter 211: optical distributor 607: time axis 608: light Power axis 701: Optical signal of wavelength λ1 702: Optical signal of wavelength λ2 703: Optical signal obtained by combining light 701 of wavelength λ1 and light 702 of wavelength λ2 706: Optical signal 701 of wavelength λ1 and optical signal 702 of wavelength λ2 Peak power P 707: DC optical power P 708 which combines optical signal 701 of wavelength λ1 and optical signal 702 of wavelength λ2: optical on state 709: optical off state

Claims (3)

【特許請求の範囲】[Claims] 【請求項1】入力された光信号を2つに分配する光分配
器と、 該光分配器の一方の分配出力の光信号に対し、論理符号
反転および波長変更の操作を行なう符号反転部と、 該符号反転部で処理された光信号、および、前記光分配
器の他方の分配出力の光信号を合成する光合波器と、 合成された光信号を増幅する光増幅器と、 増幅された光信号から、前記光分配器に入力される光信
号の波長の成分のみを抽出する通過波長フィルタとを備
え、 前記光合波器で合成された光信号が一定の電力レベルの
光信号となることを特徴とする光増幅装置。
1. An optical splitter for splitting an input optical signal into two, and a sign inverting unit for performing a logical sign inversion and a wavelength change operation on an optical signal output from one of the splitters. An optical multiplexer for synthesizing the optical signal processed by the sign inverting unit and the optical signal of the other distribution output of the optical distributor; an optical amplifier for amplifying the synthesized optical signal; A pass wavelength filter that extracts only a wavelength component of the optical signal input to the optical distributor from the signal, wherein the optical signal synthesized by the optical multiplexer is an optical signal having a constant power level. Characteristic optical amplifier.
【請求項2】請求項1記載の光増幅装置において、 前記符号反転部は、前記光分配器の出力信号を電気信号
に変換する光受信器と、該光受信器の出力信号の論理符
号を反転する反転増幅器と、該反転増幅器の出力信号に
従い、前記分配器に入力される波長とは異なる波長の光
信号を出力する光源とを有し、該光源の出力光が前記光
合波器で合成されることを特徴とする光増幅装置。
2. The optical amplifying device according to claim 1, wherein the code inverting unit converts an output signal of the optical distributor into an electric signal, and a logical code of the output signal of the optical receiver. An inverting amplifier for inverting, and a light source that outputs an optical signal having a wavelength different from the wavelength input to the distributor according to an output signal of the inverting amplifier, and output light of the light source is combined by the optical multiplexer. An optical amplifying device characterized by being performed.
【請求項3】請求項1記載の光増幅装置において、 前記光合波器で合成された光信号が、予め定めた電力レ
ベルの光信号となることを特徴とする光増幅装置。
3. The optical amplifying device according to claim 1, wherein the optical signal combined by said optical multiplexer is an optical signal having a predetermined power level.
JP29402997A 1997-10-27 1997-10-27 Optical amplifier Pending JPH11135862A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP29402997A JPH11135862A (en) 1997-10-27 1997-10-27 Optical amplifier

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP29402997A JPH11135862A (en) 1997-10-27 1997-10-27 Optical amplifier

Publications (1)

Publication Number Publication Date
JPH11135862A true JPH11135862A (en) 1999-05-21

Family

ID=17802350

Family Applications (1)

Application Number Title Priority Date Filing Date
JP29402997A Pending JPH11135862A (en) 1997-10-27 1997-10-27 Optical amplifier

Country Status (1)

Country Link
JP (1) JPH11135862A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6437908B2 (en) 2000-02-03 2002-08-20 Matsushita Electric Industrial Co., Ltd. Optical amplifying device
JP2007124472A (en) * 2005-10-31 2007-05-17 Yokogawa Electric Corp Optical communication unit
JP2009123808A (en) * 2007-11-13 2009-06-04 Nippon Telegr & Teleph Corp <Ntt> Optical amplifier and optical transmission system
JPWO2008105202A1 (en) * 2007-02-26 2010-06-03 カナレ電気株式会社 Optical fiber transmission device and optical communication network

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6437908B2 (en) 2000-02-03 2002-08-20 Matsushita Electric Industrial Co., Ltd. Optical amplifying device
US6496304B2 (en) 2000-02-03 2002-12-17 Matsushita Electric Industrial Co., Ltd. Optical amplifying device
USRE40270E1 (en) 2000-02-03 2008-04-29 Matsushita Electric Industrial Co., Ltd. Optical amplifying device
JP2007124472A (en) * 2005-10-31 2007-05-17 Yokogawa Electric Corp Optical communication unit
JPWO2008105202A1 (en) * 2007-02-26 2010-06-03 カナレ電気株式会社 Optical fiber transmission device and optical communication network
JP2009123808A (en) * 2007-11-13 2009-06-04 Nippon Telegr & Teleph Corp <Ntt> Optical amplifier and optical transmission system

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