JPH10163978A - Bidirectional amplification/transmission method - Google Patents
Bidirectional amplification/transmission methodInfo
- Publication number
- JPH10163978A JPH10163978A JP8316197A JP31619796A JPH10163978A JP H10163978 A JPH10163978 A JP H10163978A JP 8316197 A JP8316197 A JP 8316197A JP 31619796 A JP31619796 A JP 31619796A JP H10163978 A JPH10163978 A JP H10163978A
- Authority
- JP
- Japan
- Prior art keywords
- optical
- wavelength
- demultiplexer
- communication station
- multiplexer
- 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.)
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Links
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- Lasers (AREA)
- Optical Communication System (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、双方向増幅伝送方
法に関する。[0001] The present invention relates to a bidirectional amplification transmission method.
【０００２】[0002]
【従来の技術】一方の光通信局と、加入者すなわち他方
の光通信局との間を一本の光伝送路で接続し、一方の光
通信局から送信した波長１．５５μｍの信号光を他方の
光通信局で受信し、他方の光通信局から送信した波長
１．３μｍの信号光を一方の光通信局で受信することに
より、電話、ファクシミリ、画像等の情報信号を双方向
に伝送するいわゆるＦＴＴＨ（Fiber to the Home)の開
発が活発になってきた。2. Description of the Related Art One optical communication station is connected to a subscriber, that is, the other optical communication station, by one optical transmission line, and a signal light having a wavelength of 1.55 μm transmitted from one optical communication station is transmitted. Information signals such as telephone, facsimile, and images are transmitted bidirectionally by receiving the signal light of 1.3 μm wavelength transmitted from the other optical communication station and transmitted from the other optical communication station. The development of so-called FTTH (Fiber to the Home) has become active.
【０００３】図７は双方向伝送方法の従来例のブロック
図である。FIG. 7 is a block diagram of a conventional example of a bidirectional transmission method.
【０００４】一方の光通信局（図の左側）ＳA の光送信
機１５から情報信号がのった波長１．５５μｍの信号光
が発生すると、信号光が矢印１−１方向に伝搬し、光合
分波器７−１に入力される。この光合分波器７−１は、
波長１．５５μｍの信号光を通過させ、波長１．３μｍ
の信号光を分波する機能を有する。[0004] When one of the optical communication station (left side of Figure) S signal light having a wavelength of 1.55μm which information signals from the optical transmitter 15 is superimposed on the A occurs, the signal light is propagated to the arrow 1-1 direction, The signal is input to the optical multiplexer / demultiplexer 7-1. This optical multiplexer / demultiplexer 7-1 includes:
1.55 μm wavelength signal light is passed, and 1.3 μm wavelength
Has a function of demultiplexing the signal light.
【０００５】光合分波器７−１に入力した波長１．５５
μｍの信号光はこの光合分波器７−１を通って矢印１−
２、１−３方向に伝送路Ｌとしての光ファイバ１６内を
伝搬し、光合分波器７−２に入力される。光合分波器７
−２も光合分波器７−１と同様の特性を有するものであ
り、波長１．５５μｍの信号光は矢印１−３方向から矢
印１−４方向に光合分波器７−２を通って光受信機１４
−１で受信され、情報信号が再生される。The wavelength 1.55 input to the optical multiplexer / demultiplexer 7-1
The .mu.m signal light passes through the optical multiplexer / demultiplexer 7-1 and is indicated by an arrow 1-.
The light propagates through the optical fiber 16 as the transmission line L in the directions 2 and 1-3, and is input to the optical multiplexer / demultiplexer 7-2. Optical multiplexer / demultiplexer 7
-2 also has the same characteristics as the optical multiplexer / demultiplexer 7-1, and the signal light having a wavelength of 1.55 μm passes through the optical multiplexer / demultiplexer 7-2 from the direction of arrow 1-3 to the direction of arrow 1-4. Optical receiver 14
-1 and the information signal is reproduced.
【０００６】他方の光通信局（図の右側）ＳB の光送信
機１５−１から情報信号がのった波長１．３μｍの信号
光が発生すると、矢印２−１方向に伝搬して光合分波器
７−２に入力される。光合分波器７−２に入力した信号
光は矢印２−２，２−３方向に光ファイバ１６内を伝搬
し、光合分波器７−１に光合分波器７−１に入力され
る。波長１．３μｍの信号光は光合分波器７−１で分波
されて矢印２−４方向に伝搬して光受信機１４に入力さ
れ、情報信号が再生される。[0006] The other optical communication station (right side of figure) S signal light wavelength 1.3μm information signal from the optical transmitter 15-1 is superimposed on the B occurs, the optical multiplexer propagates the arrow 2-1 direction The signal is input to the duplexer 7-2. The signal light input to the optical multiplexer / demultiplexer 7-2 propagates through the optical fiber 16 in the directions of arrows 2-2 and 2-3, and is input to the optical multiplexer / demultiplexer 7-1. . The 1.3 μm wavelength signal light is split by the optical multiplexer / demultiplexer 7-1, propagates in the direction of arrow 2-4, is input to the optical receiver 14, and the information signal is reproduced.
【０００７】[0007]
【発明が解決しようとする課題】しかしながら、図７に
示した従来例には以下のような問題がある。However, the conventional example shown in FIG. 7 has the following problems.
【０００８】(1) 両光通信局ＳA ，ＳB 間の伝送距離が
長くなった場合、すなわち光ファイバ１６を長くしたい
場合には、光送信機１５、１５−１の光パワーを大きく
しなければならない。しかし、光送信機１５、１５−１
の光パワーには上限があり、光ファイバ１６の長さにも
上限（約１０Ｋｍ）があるので１０Ｋｍを超える長距離
通信は困難である。(1) If the transmission distance between the two optical communication stations S A and S B is long, that is, if the length of the optical fiber 16 is to be increased, the optical power of the optical transmitters 15 and 15-1 is increased. There must be. However, the optical transmitters 15, 15-1
Has an upper limit, and the length of the optical fiber 16 also has an upper limit (approximately 10 km), so that long-distance communication exceeding 10 km is difficult.
【０００９】(2) 光受信機１４、１４−１のクロストー
ク特性を向上させる（＜−３０ｄＢ）ためには、光合分
波器７−１、７−２における波長１．３μｍの信号光と
波長１．５５μｍの信号光とのアイソレーション特性を
−４０ｄＢ以下にする必要がある。そのためには、波長
選択機能を有する光フィルタ（方向性結合器型光フィル
タ、干渉膜型光フィルタ、マッハツェンダ型光フィルタ
等）を少なくとも２段カスケード接続しなければならな
い。このような光フィルタを複数段カスケード接続する
と、過剰損失が増加し、伝送距離に制約を受け、しかも
コスト的に高いものとなってしまう。(2) In order to improve the crosstalk characteristics of the optical receivers 14 and 14-1 (<−30 dB), a signal light having a wavelength of 1.3 μm in the optical multiplexer / demultiplexers 7-1 and 7-2 is used. It is necessary to make the isolation characteristics with the signal light having a wavelength of 1.55 μm -40 dB or less. For this purpose, at least two-stage cascade connection of an optical filter having a wavelength selection function (a directional coupler optical filter, an interference film optical filter, a Mach-Zehnder optical filter, etc.) must be performed. When such optical filters are cascaded in a plurality of stages, excess loss increases, transmission distance is restricted, and the cost is high.
【００１０】(3) 加入希望者数が増加した場合に、光通
信局ＳB の数を増設する余裕がない。[0010] (3) If the subscriber seekers the number has increased, there is no room for expansion of the number of optical communication stations S B.
【００１１】(4) 伝送距離を延ばすために、伝送路Ｌの
途中に光増幅器を挿入することが考えられるが、上記
(2) で示した波長１．３μｍの信号光と波長１．５５μ
ｍの信号光とのアイソレーション特性を、光増幅器の増
幅度分だけさらに高くしなければならず、光フィルタを
３段以上カスケード接続しなければならない。(4) To extend the transmission distance, it is conceivable to insert an optical amplifier in the middle of the transmission line L.
The signal light having a wavelength of 1.3 μm and the wavelength of 1.55 μm shown in (2)
The isolation characteristic from the signal light of m must be further increased by the amplification degree of the optical amplifier, and the optical filters must be cascaded in three or more stages.
【００１２】そこで、本発明の第１の目的は、上記課題
を解決し、伝送距離が長い双方向増幅伝送方法を提供す
ることにあり、第２の目的は、クロストーク特性に優れ
た双方向増幅伝送方法を提供することにあり、第３の目
的は加入者数の増加に対応できる双方向増幅伝送方法を
提供することにある。Accordingly, a first object of the present invention is to solve the above-mentioned problems and to provide a bidirectional amplification transmission method having a long transmission distance, and a second object is to provide a bidirectional amplification method having excellent crosstalk characteristics. It is an object of the present invention to provide an amplified transmission method, and a third object is to provide a bidirectional amplified transmission method capable of coping with an increase in the number of subscribers.
【００１３】[0013]
【課題を解決するための手段】上記目的を達成するため
に本発明は、一方の光通信局と他方の光通信局とを一本
の光伝送路で接続し、光伝送路内に少なくとも二つの波
長の異なる信号光を双方向に伝送する双方向伝送方法に
おいて、一方の光通信局は光送信機、光受信機、第１の
波長用光増幅器、第２の波長用光増幅器及び光合分波器
を有すると共に、他方の光通信局は光送信機、光受信機
及び光合分波器を有し、一方の光通信局は一方の光送信
機から第１の波長の信号光を第１の波長用の光増幅器、
一方の光合分波器、光伝送路及び他方の光合分波器を介
して他方の光受信機に送信し、他方の光通信局は他方の
光送信機から第２の波長の信号光を他方の光合分波器、
光伝送路、一方の光合分波器、第２の波長用光増幅器を
介して一方の光受信機に送信するものである。In order to achieve the above object, the present invention provides a method for connecting one optical communication station to another optical communication station via one optical transmission line, and providing at least two optical communication stations in the optical transmission line. In a two-way transmission method for transmitting two signal lights having different wavelengths in two directions, one optical communication station includes an optical transmitter, an optical receiver, a first wavelength optical amplifier, a second wavelength optical amplifier, and an optical coupling / combining device. The other optical communication station has an optical transmitter, an optical receiver, and an optical multiplexer / demultiplexer, and one optical communication station transmits a signal light of a first wavelength from one optical transmitter to the first optical communication station. Optical amplifier for the wavelength of
One optical multiplexer / demultiplexer, an optical transmission line, and the other optical multiplexer / demultiplexer transmit to the other optical receiver, and the other optical communication station transmits the signal light of the second wavelength from the other optical transmitter to the other optical receiver. Optical multiplexer / demultiplexer,
The signal is transmitted to one optical receiver via an optical transmission line, one optical multiplexer / demultiplexer, and a second wavelength optical amplifier.
【００１４】上記構成に加え本発明は、一方の光通信局
は、第１の波長用光増幅器にカスケード接続された第１
の波長用光アイソレータを有し、一方の光送信機からの
信号光を第１の波長用光アイソレータを介して第１の波
長用光増幅器で増幅した後光合波器及び光伝送路を介し
て他方の光通信局へ送信するようにしてもよい。According to the present invention, in addition to the above configuration, one of the optical communication stations includes a first optical communication station cascaded to a first wavelength optical amplifier.
And the signal light from one of the optical transmitters is amplified by the first wavelength optical amplifier via the first wavelength optical isolator and then via the optical multiplexer and the optical transmission line. You may make it transmit to the other optical communication station.
【００１５】上記構成に加え本発明は、一方の光通信局
は、第２の波長用光増幅器にカスケード接続された第２
の波長用光アイソレータを有し、他方の光通信局からの
信号光を第２の波長用光アイソレータを介して第２の波
長用光増幅器で増幅した後一方の光受信機で受信するよ
うにしてもよい。In addition to the above configuration, according to the present invention, one of the optical communication stations includes a second cascade-connected optical amplifier for a second wavelength.
And the signal light from the other optical communication station is amplified by the second wavelength optical amplifier via the second wavelength optical isolator and then received by one of the optical receivers. You may.
【００１６】また、本発明は、一方の光通信局と、他方
のＭ箇所の光通信局とを一本の光伝送路及び１×Ｍ型光
スターカプラで接続し、光伝送路内に少なくとも二つの
波長の異なる信号光を双方向に伝送する双方向伝送方法
において、一方の光通信局は光送信機、光受信機、第１
の波長用光増幅器、第２の波長用光増幅器及び光合分波
器を有すると共に、他方の光通信局は光送信機、光受信
機及び光合分波器をそれぞれ有し、一方の光通信局は一
方の光送信機から第１の波長の信号光を第１の波長用の
光増幅器、一方の光合分波器、光伝送路、１×Ｍ型光ス
ターカプラ及び他方の光合分波器を介して他方の光受信
機に送信し、他方の光通信局は他方の光送信機から第２
の波長の信号光を他方の光合分波器、１×Ｍ型光スター
カプラ、光伝送路、一方の光合分波器、第２の波長用光
増幅器を介して一方の光受信機に送信するものである。Further, according to the present invention, one optical communication station and the other M optical communication stations are connected by one optical transmission line and a 1 × M optical star coupler, and at least In a bidirectional transmission method for transmitting signal light having two different wavelengths in two directions, one optical communication station includes an optical transmitter, an optical receiver, and a first optical communication station.
And the other optical communication station has an optical transmitter, an optical receiver, and an optical multiplexer / demultiplexer, respectively. Transmits the signal light of the first wavelength from one optical transmitter to an optical amplifier for the first wavelength, one optical multiplexer / demultiplexer, an optical transmission line, a 1 × M-type optical star coupler, and the other optical multiplexer / demultiplexer. To the other optical receiver, and the other optical communication station receives a second signal from the other optical transmitter.
Is transmitted to one optical receiver via the other optical multiplexer / demultiplexer, the 1 × M-type optical star coupler, the optical transmission line, the one optical multiplexer / demultiplexer, and the second wavelength optical amplifier. Things.
【００１７】上記構成に加え本発明は、一方の光通信局
は、第１の波長用光増幅器にカスケード接続された第１
の波長用光アイソレータを有し、一方の光送信機からの
信号光を第１の波長用光アイソレータを介して第１の波
長用光増幅器で増幅した後光合波器及び光伝送路を介し
て他方の光通信局へ送信するようにしてもよい。In addition to the above configuration, according to the present invention, one of the optical communication stations includes a first optical communication station cascaded to a first wavelength optical amplifier.
And the signal light from one of the optical transmitters is amplified by the first wavelength optical amplifier via the first wavelength optical isolator and then via the optical multiplexer and the optical transmission line. You may make it transmit to the other optical communication station.
【００１８】上記構成に加え本発明は、一方の光通信局
は、第２の波長用光増幅器にカスケード接続された第２
の波長用光アイソレータを有し、他方の光通信局からの
信号光を第２の波長用光アイソレータを介して第２の波
長用光増幅器で増幅した後一方の光受信機で受信するよ
うにしてもよい。In addition to the above configuration, according to the present invention, one of the optical communication stations includes a second optical communication station connected in cascade to a second wavelength optical amplifier.
And the signal light from the other optical communication station is amplified by the second wavelength optical amplifier via the second wavelength optical isolator and then received by one of the optical receivers. You may.
【００１９】上記構成に加え本発明は、第１の波長が
１．５５μｍ帯であり、第２の波長が１．３μｍ帯であ
るか又は第１の波長が１．３μｍ帯であり、第２の波長
が１．５５μｍ帯であるのが好ましい。According to the present invention, in addition to the above-described structure, the first wavelength is in the 1.55 μm band and the second wavelength is in the 1.3 μm band, or the first wavelength is in the 1.3 μm band, and the second wavelength is in the 1.3 μm band. Is preferably in the 1.55 μm band.
【００２０】さらに本発明は、一方の光通信局と、他方
のＭ箇所の光通信局とを一本の光伝送路及び１×Ｍ型光
スターカプラで接続し、光伝送路内に少なくとも二つの
波長の異なる信号光を双方向に伝送する双方向伝送方法
において、一方の光通信局は光送信機、光受信機、第１
の波長用光増幅器、第２の波長用光増幅器及び光合分波
器を有すると共に、他方の光通信局は光送信機、光受信
機及び光合分波器をそれぞれ有し、一方の光通信局は一
方の光送信機から第１の波長の信号光を第１の波長用の
光増幅器、一方の光合分波器、光伝送路、１×Ｍ型光ス
ターカプラ及び他方の光合分波器を介して他方の光受信
機に送信し、他方の各光通信局は他方の各光送信機から
第２の波長を含む波長帯の信号光のうち波長帯をＭ分配
して異ならせた信号光を、他方の光合分波器、１×Ｍ型
光スターカプラ、光伝送路を介して、一方の光通信局へ
送信すると共に、一方の光通信局では光受信機と光合分
波器との間に設けられたチューナブル光フィルタによっ
て上記波長帯の信号光をチューニングして選択的に受信
するものである。Further, according to the present invention, one optical communication station and the other M optical communication stations are connected by one optical transmission line and a 1 × M optical star coupler, and at least two optical communication stations are connected in the optical transmission line. In the two-way transmission method for transmitting two signal lights having different wavelengths in two directions, one optical communication station includes an optical transmitter, an optical receiver, and a first optical communication station.
And the other optical communication station has an optical transmitter, an optical receiver, and an optical multiplexer / demultiplexer, respectively. Transmits the signal light of the first wavelength from one optical transmitter to an optical amplifier for the first wavelength, one optical multiplexer / demultiplexer, an optical transmission line, a 1 × M-type optical star coupler, and the other optical multiplexer / demultiplexer. The other optical communication station transmits the signal light from the other optical transmitter to the other optical receiver by dividing the wavelength band of the signal light of the wavelength band including the second wavelength into M and making the signal light different. Is transmitted to one of the optical communication stations via the other optical multiplexer / demultiplexer, the 1 × M-type optical star coupler, and the optical transmission line, and the optical receiver and optical multiplexer / demultiplexer are connected at one optical communication station. The signal light in the above-mentioned wavelength band is tuned by a tunable optical filter provided therebetween, and selectively tuned.
【００２１】本発明によれば、一方の光通信局内で信号
光を増幅した後一本の光伝送路を介して他方の光通信局
に送信すると共に、他方の光通信局から光伝送路を介し
て送信された信号光を一方の光通信局内で増幅した後受
信することにより、光伝送路内を双方向に伝搬する、波
長の異なった信号光を略同程度の増幅度で増幅すること
ができ、長距離伝送を実現することができる。According to the present invention, the signal light is amplified in one optical communication station and then transmitted to the other optical communication station via one optical transmission path, and the optical transmission path is transmitted from the other optical communication station. Amplifying signal light of different wavelengths, which propagates in both directions in an optical transmission line, with approximately the same degree of amplification by amplifying the signal light transmitted through the optical communication station and receiving it And long-distance transmission can be realized.
【００２２】一般に、双方向伝送路内に光増幅器を挿入
すると、波長の異なった信号光間のアイソレーション特
性が問題となり、クロストーク特性の劣化を誘引する
が、第１の波長用の光アイソレータと第２の波長用の光
アイソレータとを用いることにより、高いアイソレーシ
ョン特性を得ることができる。また、増幅に伴って問題
となる増幅された信号光の反射光も抑圧することがで
き、これによる異なった波長の信号光間のクロストーク
特性が劣化することがない。さらに、光アイソレータを
用いることにより、光送信機側への反射戻り光による波
長変動と出力変動とを抑圧することができる。In general, when an optical amplifier is inserted in a bidirectional transmission line, isolation characteristics between signal lights having different wavelengths become a problem, and crosstalk characteristics are deteriorated. However, an optical isolator for the first wavelength is used. And the optical isolator for the second wavelength, high isolation characteristics can be obtained. In addition, the reflected light of the amplified signal light, which becomes a problem with the amplification, can also be suppressed, so that the crosstalk characteristics between signal lights of different wavelengths do not deteriorate. Further, by using the optical isolator, it is possible to suppress wavelength fluctuation and output fluctuation due to reflected return light to the optical transmitter side.
【００２３】双方向伝送用の信号光の波長が１．３μｍ
帯及び１．５５μｍ帯の場合には、１．３μｍ帯（或い
は１．５５μｍ帯）用光アイソレータが、１．５５μｍ
帯（或いは１．３μｍ帯）の信号光に対して高い波長分
離度と高い伝搬阻止力を有するので、これを光合分波器
と組み合わせることにより、十分に高いアイソレーショ
ン特性を確保でき、各光通信局内での光送信機から光受
信機への別波長信号光の漏れ込みや、増幅された信号光
の伝送路からの反射戻り光の光受信機への漏れ込みを十
分小さく抑えることができる。The wavelength of the signal light for bidirectional transmission is 1.3 μm
Band and 1.55 μm band, the optical isolator for 1.3 μm band (or 1.55 μm band) is 1.55 μm band.
Since it has a high wavelength separation degree and a high propagation blocking power for signal light in the band (or 1.3 μm band), by combining this with an optical multiplexer / demultiplexer, a sufficiently high isolation characteristic can be ensured and each light In the communication station, leakage of the signal light of another wavelength from the optical transmitter to the optical receiver and leakage of the reflected return light from the transmission line of the amplified signal light into the optical receiver can be sufficiently suppressed. .
【００２４】光合分波器は一段構成のものでよく、低損
失で小さなサイズのものを用いることができる。The optical multiplexer / demultiplexer may have a single-stage configuration, and a low-loss and small-size optical multiplexer / demultiplexer can be used.
【００２５】両光通信局間の信号光は、それぞれ十分に
増幅されているので、システムの拡張が容易である。例
えば、光伝送路の長さを変えたり、他方の光通信局の局
数の増加、機能性光部品（例えばチューナブル光フィル
タ、外部光変調器、光分岐器等）の挿入が容易となる。Since the signal light between the two optical communication stations is sufficiently amplified, the system can be easily expanded. For example, it becomes easy to change the length of the optical transmission line, increase the number of other optical communication stations, and insert functional optical components (for example, tunable optical filters, external optical modulators, optical splitters, etc.). .
【００２６】従って、光送信機が、光アイソレータを有
するときには、信号光の光源の反射戻り光による劣化を
防止できる。その結果、長期的に安定に使用することが
でき、光受信機が、光アイソレータを有するときには、
不要光の入射を抑圧でき、高い信号雑音比（高Ｓ／Ｎ）
を実現することができる。また不要光等の雑音による光
受信機のエラーを大幅に低減することができる。Therefore, when the optical transmitter has an optical isolator, it is possible to prevent the signal light from deteriorating due to the reflected return light of the light source. As a result, it can be used stably for a long time, and when the optical receiver has an optical isolator,
High signal-to-noise ratio (high S / N) that can suppress unnecessary light incidence
Can be realized. Further, errors in the optical receiver due to noise such as unnecessary light can be significantly reduced.
【００２７】[0027]
【発明の実施の形態】以下、本発明の実施の形態を添付
図面に基づいて詳述する。Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
【００２８】図１は本発明の双方向増幅伝送方法を適用
した双方向増幅伝送システムの一実施の形態を示すブロ
ック図である。FIG. 1 is a block diagram showing an embodiment of a bidirectional amplification transmission system to which the bidirectional amplification transmission method of the present invention is applied.
【００２９】同図に示すシステムは、一方の光通信局
（図の左側、以下「Ａ局」という）ＳA と、他方の光通
信局（図の右側、以下「Ｂ局」という）ＳB とを一本の
光伝送路Ｌとしての光ファイバ（シングルモードファイ
バ、分散シフトファイバ或いはこれらのファイバと分散
補償ファイバとを接続したもの）１３で接続し、第１の
波長（以下「λ1 」という）の信号光及び第２の波長
（以下「λ2 」という）の信号光を用いて双方向増幅伝
送するものである。The system shown in FIG. (Left side in the figure, the "A station" hereinafter) one optical communication station and S A, the other optical communication station (right of the figure, hereinafter referred to as "B station") S B Are connected by an optical fiber (single mode fiber, dispersion shift fiber, or a connection of these fibers and a dispersion compensating fiber) 13 as one optical transmission line L, and a first wavelength (hereinafter referred to as “λ 1 ”). ) And a signal light of a second wavelength (hereinafter referred to as “λ 2 ”).
【００３０】Ａ局ＳA は、波長λ1 の信号光を発生する
光送信機１５と、入力端が光送信機１５の出力端に接続
された光アイソレータ１０−１と、波長０．９８μｍ帯
（或いは１．４８μｍ帯）の励起光を発生する励起光源
（例えば半導体レーザ）４−１と、一方の入力端７−１
ａが励起光源４−１の出力端に接続され、他方の入力端
７−１ｂが光アイソレータ１０−１の出力端に接続され
たＷＤＭ(WavelengthDivision Multiplexing ：波長多
重伝送）カプラ７−１と、一端がＷＤＭカプラ７−１の
一方の出力端７−１ｃに接続されたＥｒ添加光ファイバ
８と、一方の入力端７−２ａがＥｒ添加光ファイバ８の
他端に接続されたＷＤＭカプラ７−２と、一方の入力端
１２−１ａがＷＤＭカプラ７−２の一方の出力端７−２
ｂに接続された一方の光合分波器１２−１と、一方の入
力端１６−１ａが光合分波器１２−１の一方の出力端１
２−１ｂに接続されたＷＤＭカプラ１６−１と、出力端
がＷＤＭ１６−１カプラの他方の入力端１６−１ｂに接
続され波長０．８μｍ帯の励起光を発生する励起光源
（例えば半導体レーザ）５−１と、一端（図では右側）
がＷＤＭカプラ１６−１の一方の出力端１６−１ｃに接
続されたＰｒ添加光ファイバ９と、一方の入力端１６−
２ａにＰｒ添加光ファイバ９の他端（図では左側）が接
続されたＷＤＭカプラ１６−２と、入力端がＷＤＭカプ
ラ１６−２の一方の出力端１６−２ｂに接続された光ア
イソレータ１１−１と、光アイソレータ１１−１の出力
端に接続された光受信機１４とで構成されている。[0030] A station S A includes an optical transmitter 15 for generating a signal light of the wavelength lambda 1, the optical isolator 10-1 having an input connected to the output end of the optical transmitter 15, the wavelength 0.98μm band (Or a 1.48 μm band) excitation light source (for example, a semiconductor laser) 4-1 for generating excitation light, and one input terminal 7-1
a is connected to the output end of the pump light source 4-1, and the other input end 7-1b is connected to the output end of the optical isolator 10-1; a WDM (Wavelength Division Multiplexing) coupler 7-1; Are an Er-doped optical fiber 8 connected to one output terminal 7-1c of the WDM coupler 7-1, and a WDM coupler 7-2 whose one input terminal 7-2a is connected to the other end of the Er-doped optical fiber 8. And one input terminal 12-1a is connected to one output terminal 7-2 of the WDM coupler 7-2.
b, and one input terminal 16-1a is connected to one output terminal 1 of the optical multiplexer / demultiplexer 12-1.
WDM coupler 16-1 connected to 2-1b, and an excitation light source (for example, a semiconductor laser) whose output end is connected to the other input end 16-1b of the WDM 16-1 coupler and generates excitation light in the 0.8 μm band. 5-1 and one end (right side in the figure)
Is a Pr-doped optical fiber 9 connected to one output terminal 16-1c of the WDM coupler 16-1, and one input terminal 16-c.
A WDM coupler 16-2 having the other end (left side in the figure) of the Pr-doped optical fiber 9 connected to 2a, and an optical isolator 11- having an input end connected to one output end 16-2b of the WDM coupler 16-2. 1 and an optical receiver 14 connected to the output end of the optical isolator 11-1.
【００３１】これら励起光源４−１、ＷＤＭカプラ７−
１及びＥｒ添加光ファイバ８で第１の波長用光増幅器Ａ
１が構成されており、励起光源５−１、ＷＤＭカプラ１
６−１及びＰｒ添加光ファイバ９で第２の波長用光増幅
器Ａ２が構成されている。The excitation light source 4-1 and the WDM coupler 7-
1 and an Er-doped optical fiber 8 for the first wavelength optical amplifier A
, A pump light source 5-1, a WDM coupler 1
The 6-1 and Pr-doped optical fiber 9 constitute a second wavelength optical amplifier A2.
【００３２】Ｂ局ＳB は、波長１．３μｍ帯（λ2 ）の
信号光を発生する光送信機１５−１と、入力端が光送信
機１５−１の出力端に接続された光アイソレータ１１−
２と、一方の入力端１２−２ａが光アイソレータ１１−
２の出力端に接続された他方の光合分波器１２−２と、
入力端が光合分波器１２−２の一方の出力端１２−１ｂ
に接続された光アイソレータ１−６と、光アイソレータ
１−６の出力端に接続された光受信機１４−１とで構成
されている。[0032] B station S B includes an optical transmitter 15-1 which generates the signal light of the wavelength of 1.3μm band (lambda 2), an optical isolator having an input connected to the output end of the optical transmitter 15-1 11-
2 and one input terminal 12-2a are connected to the optical isolator 11-
2, the other optical multiplexer / demultiplexer 12-2 connected to the output end of
The input terminal is one output terminal 12-1b of the optical multiplexer / demultiplexer 12-2.
And an optical receiver 14-1 connected to the output end of the optical isolator 1-6.
【００３３】Ａ局ＳA の光送信機１５から波長λ1 の信
号光が発生すると、信号光は矢印１−１の方向に伝搬し
光アイソレータ１０−１を通ってＷＤＭカプラ７−１に
入力される。このＷＤＭカプラ７−１で励起光源４−１
からの励起光と合流してＥｒ添加光ファイバ８内に矢印
１−２、３−２方向に入力される。Ｅｒ添加光ファイバ
８を伝搬した信号光は矢印１−３方向に伝搬し、ＷＤＭ
カプラ７−２を通って光合分波器１２−１に入力され
る。[0033] When A station S wavelength lambda 1 of the signal light from the optical transmitter 15 of A occurs, the input to the WDM coupler 7-1 signal light passes through the optical isolator 10-1 propagates in the direction of arrow 1-1 Is done. The WDM coupler 7-1 uses the excitation light source 4-1.
And is input into the Er-doped optical fiber 8 in the directions of arrows 1-2 and 3-2. The signal light propagating through the Er-doped optical fiber 8 propagates in the direction of arrow 1-3, and
The light is input to the optical multiplexer / demultiplexer 12-1 through the coupler 7-2.
【００３４】ここで、矢印３−２方向に伝搬する励起光
はＥｒ添加光ファイバ８内を伝搬する際にその大部分が
Ｅｒ添加光ファイバ８内で吸収されるが、一部の吸収さ
れなかった励起光はＷＤＭカプラ７−３の他方の出力端
７−２ｃから矢印３−３方向に放出される。Here, most of the pumping light propagating in the direction of arrow 3-2 is absorbed in the Er-doped optical fiber 8 when propagating in the Er-doped optical fiber 8, but is not partially absorbed. The pumping light is emitted from the other output terminal 7-2c of the WDM coupler 7-3 in the direction of arrow 3-3.
【００３５】このように、光増幅器Ａ１のＥｒ添加光フ
ァイバ８内で矢印３−２方向に伝搬する励起光が吸収さ
れることにより、波長λ1 の信号光の強度が数百倍から
１万倍に増幅される。このような増幅作用により伝送路
Ｌである光ファイバ１３の長さを従来の１０倍以上の長
さに延長することができる。As described above, by absorbing the pump light propagating in the direction of arrow 3-2 in the Er-doped optical fiber 8 of the optical amplifier A1, the intensity of the signal light having the wavelength λ 1 is increased several hundred times to 10,000. It is amplified twice. By such an amplifying action, the length of the optical fiber 13 as the transmission line L can be extended to ten times or more the length of the conventional one.
【００３６】尚、光アイソレータ１０−１は、波長１．
５５μｍ帯の信号光のみを順方向（矢印方向）に通過さ
せ、逆方向（矢印と反対の方向）に伝搬する波長１．５
５帯、０．９８μｍ帯、１．３μｍ帯及び１．４８μｍ
帯の信号光の伝搬を阻止する機能を有している。ＷＤＭ
カプラ７−１、７−２は、波長０．９８μｍ帯（或いは
１．４８μｍ帯）の励起光を矢印３−１から矢印３−２
方向に分波して伝搬させ、波長λ1 の信号光を矢印１−
１方向から矢印１−２方向へ通過させる波長選択型光フ
ィルタである。The optical isolator 10-1 has a wavelength of 1.
Only the signal light in the 55 μm band is transmitted in the forward direction (the direction of the arrow) and propagates in the reverse direction (the direction opposite to the arrow) at a wavelength of 1.5.
5 bands, 0.98 μm band, 1.3 μm band and 1.48 μm
It has a function of blocking propagation of band signal light. WDM
The couplers 7-1 and 7-2 supply the pumping light having a wavelength of 0.98 μm band (or 1.48 μm band) from the arrow 3-1 to the arrow 3-2.
The signal light of wavelength λ 1 is propagated by the arrow 1-
This is a wavelength-selective optical filter that allows light to pass from one direction in the direction of arrow 1-2.
【００３７】光合分波器１２−１は、波長λ1 の信号光
を矢印１−３方向から矢印１−４方向に通過させ、波長
λ2 の信号光を矢印２−３方向から矢印２−４方向に分
波させる方向性結合器構造の波長選択型光フィルタであ
る。The demultiplexer 12-1, the signal light of the wavelength lambda 1 is passed from the arrow 1-3 direction of arrow 1-4 direction arrow signal light of the wavelength lambda 2 from the arrow 2-3 direction of 2- This is a wavelength-selective optical filter having a directional coupler structure that splits light in four directions.
【００３８】従来の構成では、光合分波器１２−１に波
長選択型光フィルタを少なくとも２段カスケード接続し
ないと波長λ1 の信号光と波長λ2 の信号光との間の光
アイソレーション特性を十分に大きくとることができな
かった。In the conventional configuration, the optical isolation characteristics between the signal light of wavelength λ 1 and the signal light of wavelength λ 2 are required unless at least two stages of wavelength selective optical filters are cascade-connected to the optical multiplexer / demultiplexer 12-1. Couldn't be large enough.
【００３９】これに対して図１に示したシステムは、十
分に大きな光アイソレーション特性と一方通行特性とを
有する光アイソレータ１０−１、１０−２、１１−１、
１１−２を光送信機１５、１５−１の出力側と光受信機
１４、１４−１の入力側にそれぞれ設けたので、光合分
波器１２−１、１２−２は、光アイソレーション特性の
大きくない通常の方向性結合機構造の光フィルタを用い
ることができる。On the other hand, the system shown in FIG. 1 has the optical isolators 10-1, 10-2, 11-1,... Having sufficiently large optical isolation characteristics and one-way characteristics.
11-2 are provided on the output side of the optical transmitters 15 and 15-1 and on the input side of the optical receivers 14 and 14-1, respectively, so that the optical multiplexer / demultiplexers 12-1 and 12-2 have optical isolation characteristics. An optical filter having a normal directional coupler structure, which is not large, can be used.
【００４０】光合分波器１２−１を通過し、矢印１−４
方向に伝搬する波長λ1 の信号光は、光ファイバ１３内
を矢印１−５方向に伝搬し、光合分波器１２−２の出入
力端１２−２ｃに入力される。この光合分波器１２−２
は、光合分波器１２−１と同様の特性を有している。After passing through the optical multiplexer / demultiplexer 12-1, arrows 1-4
The signal light of wavelength λ 1 propagating in the direction propagates in the optical fiber 13 in the direction of arrow 1-5 and is input to the input / output terminal 12-2c of the optical multiplexer / demultiplexer 12-2. This optical multiplexer / demultiplexer 12-2
Has the same characteristics as the optical multiplexer / demultiplexer 12-1.
【００４１】光ファイバ１３中を矢印１−５方向に送信
される波長λ1 の信号光は、Ｂ局ＳB 側の光合分波器１
２−２を通過した後光アイソレータ１０−２を通過し、
光受信機１４−１で受信される。The signal light of wavelength lambda 1 transmitted through the optical fiber 13 in the arrow 1-5 direction, B station S B side of the optical multiplexer 1
After passing through 2-2, pass through the optical isolator 10-2,
It is received by the optical receiver 14-1.
【００４２】他方、Ｂ局ＳB 側の光送信機１５−１で発
生した波長λ2 （１．３μｍ帯）の信号光は矢印２−１
方向に伝搬し、波長１．３μｍ帯の信号光のみ矢印方向
に通過させる光アイソレータ１１−２を通って光合分波
器１２−２に入力される。この光アイソレータ１１−２
も逆方向（矢印と反対方向）に伝搬する波長１．３μｍ
帯、０．９８μｍ帯、１．４８μｍ帯及び１．５５μｍ
帯の光の伝搬を阻止する特性を有する。光合分波器１２
−２に入力された波長λ2 の信号光は矢印２−２方向に
分波されて光ファイバ１３内を矢印２−３方向に送信さ
れ、光合分波器１２−１の入出力端１２−１ｃに入力さ
れる。光合分波器１２−１に入力された信号光は分波さ
れ、ＷＤＭカプラ１６−１を通って矢印２−４方向に伝
搬し、Ｐｒ添加光ファイバ９内に入力される。このＰｒ
添加光ファイバ９内には、励起光源５−１から矢印６−
１方向に伝搬する励起光がＷＤＭカプラ１６−１を通っ
て矢印６−２方向に入力され、Ｐｒ添加光ファイバ９内
を伝搬することにより、Ｐｒに吸収されて反転分布状態
を形成し、矢印２−４方向に伝搬する波長λ2 の信号光
が数百倍から１万倍に増幅されて矢印２−５方向に伝搬
する。[0042] On the other hand, the signal light of the B station S B-side wavelength lambda 2 generated by the optical transmitter 15-1 (1.3 .mu.m band) arrows 2-1
The optical signal is transmitted to the optical multiplexer / demultiplexer 12-2 through the optical isolator 11-2 that transmits only the 1.3 μm wavelength signal light in the direction of the arrow. This optical isolator 11-2
Is also 1.3 μm which propagates in the opposite direction (the direction opposite to the arrow)
Band, 0.98 μm band, 1.48 μm band and 1.55 μm
It has the property of blocking the propagation of band light. Optical multiplexer / demultiplexer 12
The signal light of wavelength λ 2 input to −2 is demultiplexed in the direction of the arrow 2-2 and transmitted in the optical fiber 13 in the direction of the arrow 2-3, and the input / output end 12− of the optical multiplexer / demultiplexer 12-1. 1c. The signal light input to the optical multiplexer / demultiplexer 12-1 is demultiplexed, propagates through the WDM coupler 16-1 in the direction of arrow 2-4, and is input into the Pr-doped optical fiber 9. This Pr
In the addition optical fiber 9, an arrow 6-
Excitation light propagating in one direction is input in the direction of arrow 6-2 through the WDM coupler 16-1, and propagates in the Pr-doped optical fiber 9, where it is absorbed by Pr to form a population inversion state. The signal light of the wavelength λ 2 propagating in the 2-4 direction is amplified several hundred times to 10,000 times and propagates in the direction of the arrow 2-5.
【００４３】光増幅器Ａ２のＰｒ添加光ファイバ９内で
増幅された波長λ2 の信号光は、ＷＤＭカプラ１６−
２、光アイソレータ１１−１を通って矢印２−６方向に
伝搬し、光受信機１４で受信される。The signal light of the wavelength λ 2 amplified in the Pr-doped optical fiber 9 of the optical amplifier A 2 is converted to a WDM coupler 16-
2. The light propagates in the direction of arrow 2-6 through the optical isolator 11-1 and is received by the optical receiver 14.
【００４４】尚、ＷＤＭカプラ１６−１、１６−２は
０．８μｍ帯の励起光のみを分波し、波長λ2 の信号光
はそのまま通過させる波長選択型フィルタの機能を有す
る。The WDM couplers 16-1 and 16-2 have the function of a wavelength selective filter that separates only the 0.8 μm band pump light and passes the signal light of wavelength λ 2 as it is.
【００４５】Ｐｒ添加光ファイバ９内で吸収されなかっ
た残りの励起光は矢印６−３方向に分波されて放出され
る。光アイソレータ１１−１も光アイソレータ１１−２
と同様に、順方向（矢印方向）にのみ波長λ2 の信号光
を通過させ、波長０．９８μｍ帯、１．４８μｍ帯及び
１．５５μｍ帯の光の伝搬を阻止する特性を有する。上
述した光アイソレータ１０−１、１０−２、１１−１及
び１１−２の特性は現在の技術で十分に実現することが
できるものである。The remaining pump light not absorbed in the Pr-doped optical fiber 9 is split and emitted in the direction of arrow 6-3. The optical isolator 11-1 is also the optical isolator 11-2
Similarly to the above, the signal light having the wavelength λ 2 is transmitted only in the forward direction (the direction of the arrow), and has the characteristic of blocking the propagation of the light in the 0.98 μm band, the 1.48 μm band, and the 1.55 μm band. The characteristics of the optical isolators 10-1, 10-2, 11-1 and 11-2 described above can be sufficiently realized by the current technology.
【００４６】以上において、波長λ1 、λ2 の信号光の
強度はＥｒ添加光ファイバ８及びＰｒ添加光ファイバ９
で数百倍から１万倍に増幅されるので、光ファイバ１３
の伝送路長を従来のものよりも１０倍以上の長さに延長
することができる。また、両光送信機１５、１５−１の
出力側、両光受信機１４、１４−１の入力側に波長選択
特性と高い光アイソレーション特性を有する光アイソレ
ータを設けることにより、光送信機１５、１５−１と光
受信機１４、１４−１との間のアイソレーションを十分
に大きくとることができ、しかもクロストークを十分に
小さく抑えることができる。従って、光合分波器１２−
１、１２−２には簡易で、低損失、しかも低コストな光
フィルタを用いることができる。さらに、波長λ1 、λ
2 の信号光の強度がそれぞれ数百倍から１万倍に増幅さ
れ、大出力になっているにもかかわらず、これら波長間
の光の干渉は十分に小さく抑えられ、結果的に波長間の
信号光のクロストークは極めて小さなものとなる。In the above description, the intensities of the signal light having the wavelengths λ 1 and λ 2 correspond to the Er-doped optical fiber 8 and the Pr-doped optical fiber 9.
Is amplified several hundred times to 10,000 times by the optical fiber 13
Can be extended to 10 times or more the length of the conventional one. Further, by providing an optical isolator having wavelength selection characteristics and high optical isolation characteristics on the output side of both optical transmitters 15 and 15-1 and the input side of both optical receivers 14 and 14-1, the optical transmitter 15 is provided. , 15-1 and the optical receivers 14 and 14-1 can be made sufficiently large, and the crosstalk can be sufficiently suppressed. Therefore, the optical multiplexer / demultiplexer 12-
A simple, low-loss, and low-cost optical filter can be used for 1 and 12-2. Further, the wavelengths λ 1 and λ
In spite of the fact that the intensity of the signal light of No. 2 is amplified several hundred times to 10,000 times, respectively, and the output is large, the interference of light between these wavelengths is sufficiently suppressed, and as a result, the The crosstalk of the signal light becomes extremely small.
【００４７】図２は本発明の双方向増幅伝送方法を適用
した双方向増幅伝送システムの他の実施の形態を示すブ
ロック図である。尚、図１に示した実施の形態と同様の
部材には共通の符号を用いた。FIG. 2 is a block diagram showing another embodiment of the bidirectional amplification transmission system to which the bidirectional amplification transmission method of the present invention is applied. The same reference numerals are used for members similar to those in the embodiment shown in FIG.
【００４８】図１に示した双方向増幅伝送システムとの
相違点は、Ａ局において両光増幅器を光ファイバと光合
分波器との間に設けた点である。The difference from the bidirectional amplification transmission system shown in FIG. 1 is that both optical amplifiers are provided between the optical fiber and the optical multiplexer / demultiplexer at the A station.
【００４９】図２において、Ａ局ＳA の光送信機１５が
作動すると、波長λ1 の信号光が矢印１−１方向に伝搬
して光アイソレータ１０−１を通って光合分波器１２−
１の一方の入力端１２−１ａに入力される。光合分波器
１２−１を通って矢印１−２方向に伝搬する信号光が光
増幅器Ａ１のＥｒ添加光ファイバ８、光増幅器Ａ２のＷ
ＤＭカプラ１６−１、光増幅器Ａ１のＷＤＭカプラ７−
１、光増幅器Ａ２のＰｒ添加光ファイバ９を伝搬する。
光増幅器Ａ１のＥｒ添加光ファイバ８内を、励起光源４
−１からの励起光が伝搬することにより、矢印１−２方
向に伝搬する波長λ1 の信号光が増幅される。光増幅器
Ａ１で増幅された信号光は光ファイバ１３を矢印１−
３、１−４方向に伝搬し、Ｂ局ＳB の光合分波器１２−
２で分波されて光アイソレータ１０−２を通って光受信
機１４−１で受信される。In FIG. 2, when the optical transmitter 15 of the station A operates, the signal light of the wavelength λ 1 propagates in the direction of the arrow 1-1 and passes through the optical isolator 10-1 to the optical multiplexer / demultiplexer 12-.
1 is input to one input terminal 12-1a. The signal light propagating in the direction of arrow 1-2 through the optical multiplexer / demultiplexer 12-1 is the Er-doped optical fiber 8 of the optical amplifier A1 and the W of the optical amplifier A2.
DM coupler 16-1, WDM coupler 7- of optical amplifier A1
1. The light propagates through the Pr-doped optical fiber 9 of the optical amplifier A2.
In the Er-doped optical fiber 8 of the optical amplifier A1, the pump light source 4
The signal light of wavelength λ 1 propagating in the direction of arrow 1-2 is amplified by the propagation of the pump light from −1. The signal light amplified by the optical amplifier A1 passes through the optical fiber 13 by the arrow 1-.
3,1-4 propagates in the direction, of the B station S B demultiplexer 12-
The signal is demultiplexed by 2 and received by the optical receiver 14-1 through the optical isolator 10-2.
【００５０】Ｂ局ＳB の光送信機が作動すると波長λ2
の信号光が矢印２−１方向に伝搬して光アイソレータ１
１−２を通って光合分波器１２−２の入力端１２−２ａ
に入力される。光合分波器１２−２を通って矢印２−２
方向に伝搬する信号光は光ファイバ１３を伝搬し、Ａ局
ＳA の光増幅器Ａ２のＰｒ添加光ファイバ９、光増幅器
Ａ１のＷＤＭカプラ７−１、光増幅器Ａ２のＷＤＭカプ
ラ１６−１、光増幅器Ａ１のＰｒ添加光ファイバ８を矢
印２−４、３−２方向に伝搬する。光増幅器Ａ２のＰｒ
添加光ファイバ９内を、励起光源５−１からの励起光が
伝搬することにより、矢印２−３方向に伝搬する波長λ
2 の信号光が増幅される。光増幅器Ａ２で増幅された信
号光は矢印２−４方向に伝搬し光合分波器１２−１で分
波されて光アイソレータ１１−１を通って光受信機１４
で受信される。When the optical transmitter of station B operates, the wavelength λ 2
Signal light propagates in the direction of arrow 2-1 and the optical isolator 1
1-2, the input end 12-2a of the optical multiplexer / demultiplexer 12-2
Is input to Arrow 2-2 through the optical multiplexer / demultiplexer 12-2
Signal light propagating in the direction propagated through the optical fiber 13, Pr-doped optical fiber 9 of the optical amplifier A2 in the A station S A, WDM coupler 7-1 of the optical amplifier A1, WDM coupler 16-1 of the optical amplifier A2, the light The light propagates through the Pr-doped optical fiber 8 of the amplifier A1 in the directions of arrows 2-4 and 3-2. Pr of optical amplifier A2
When the pumping light from the pumping light source 5-1 propagates in the addition optical fiber 9, the wavelength λ propagates in the direction of arrow 2-3.
The signal light of 2 is amplified. The signal light amplified by the optical amplifier A2 propagates in the direction of arrow 2-4, is demultiplexed by the optical multiplexer / demultiplexer 12-1, passes through the optical isolator 11-1, and passes through the optical receiver 14.
Received at.
【００５１】尚、波長λ1 の信号光はＰｒ添加光ファイ
バ９内を伝搬しても増幅はされず若干減衰しつつ伝搬
し、波長λ2 の信号光はＥｒ添加光ファイバ８内を通過
しても増幅されず若干減衰しつつ伝搬する。The signal light having the wavelength λ 1 propagates through the Pr-doped optical fiber 9 without being amplified and propagates while being slightly attenuated. The signal light having the wavelength λ 2 passes through the Er-doped optical fiber 8. Even though it is not amplified, it propagates with some attenuation.
【００５２】光送信機１５から矢印１−１方向に伝搬す
る波長λ1 の信号光の光受信機１４への漏洩は、光合分
波器１２−１と光アイソレータ１１−１との間の高光ア
イソレーション特性により阻止される。これとは逆に、
矢印２−４方向に伝搬する波長λ2 の信号光の光送信機
１５への漏れ込みによる光送信機１５の発振波長、発振
出力の変動も光合分波器１２−１と光アイソレータ１０
−１との間の高光アイソレーション特性により阻止され
る。また、光受信機１４の光Ｓ／Ｎ（信号光／雑音）特
性も光アイソレータ１１−１の挿入により大幅に改善さ
れる。これは矢印３−１、６−１方向に伝搬する励起光
の光受信機１４内への漏れ込みが光合分波器１２−１と
光アイソレータ１１−１とで阻止することができるから
である。同様にＢ局ＳB についても高いＳ／Ｎ特性や励
起光の漏れ込み阻止が期待できる。Leakage of the signal light of wavelength λ 1 propagating in the direction of arrow 1-1 from the optical transmitter 15 to the optical receiver 14 is caused by high light between the optical multiplexer / demultiplexer 12-1 and the optical isolator 11-1. Blocked by isolation characteristics. On the contrary,
The fluctuation of the oscillation wavelength and oscillation output of the optical transmitter 15 due to the leakage of the signal light of the wavelength λ 2 propagating in the direction of the arrow 2-4 into the optical transmitter 15 is also caused by the optical multiplexer / demultiplexer 12-1 and the optical isolator 10.
It is blocked by high optical isolation characteristics between -1. Further, the optical S / N (signal light / noise) characteristics of the optical receiver 14 can be greatly improved by inserting the optical isolator 11-1. This is because the leakage of the pump light propagating in the directions of arrows 3-1 and 6-1 into the optical receiver 14 can be prevented by the optical multiplexer / demultiplexer 12-1 and the optical isolator 11-1. . Similarly high S / N characteristics and the excitation light leakage blocking also B station S B can be expected.
【００５３】すなわち、Ｂ局ＳB において光送信機１５
−１から矢印２−１方向に伝搬する波長λ2 の信号光の
光受信機１４−１への漏れ込みを阻止することができ
る。またＡ局ＳA の励起光源４−１、５−１から矢印３
−１、６−１方向に伝搬する励起光が光ファイバ１３を
伝搬してＢ局ＳB の光受信機１４−１への漏れ込みを阻
止することができ、光送信機１５−１の発振波長と出力
とを安定させることができる。[0053] That is, the optical transmitter in the station B S B 15
-1 can be prevented leakage of the light receiver 14-1 of the wavelength lambda 2 of the signal light propagating in the arrow 2-1 direction. Also, the arrow 3 from the excitation light sources 4-1 and 5-1 of the station A SA.
-1,6-1 can pump light propagating in the direction to prevent the leakage of the optical receiver 14-1 of station B S B propagates through the optical fiber 13, the oscillation of the optical transmitter 15-1 The wavelength and the output can be stabilized.
【００５４】図３は本発明の双方向増幅伝送方法を適用
した双方向増幅伝送システムの他の実施の形態を示すブ
ロック図である。FIG. 3 is a block diagram showing another embodiment of the bidirectional amplification transmission system to which the bidirectional amplification transmission method of the present invention is applied.
【００５５】図１に示した双方向増幅伝送システムとの
相違点は、他方の光通信局が複数の光通信局からなって
いる点である。The difference from the bidirectional amplification transmission system shown in FIG. 1 is that the other optical communication station comprises a plurality of optical communication stations.
【００５６】一端にＡ局ＳA が接続された光ファイバ１
３の他端に、１×Ｍ（Ｍ≧２）型の光スターカプラ１７
のポート端Ｐ0 が接続され、その光スターカプラ１７の
Ｍポート端Ｐ1 〜Ｐm にＢ局ＳB 〜Ｎ局ＳN が接続され
ている。Ｂ局ＳB 〜Ｎ局ＳN側において、光送信機１５
−１〜１５−ｍと光受信機１４−１〜１４−ｍとが、ア
イソレータ１０−２〜１０−ｎ、１１−２〜１１−ｎを
介して光合分波器１２−２〜１２−ｎの入力端と出力端
とにそれぞれ接続され、光合分波器１２−２〜１２−ｎ
の入出力端が光スターカプラ１７のポート端Ｐ1 〜Ｐm
にそれぞれ接続されている。[0056] optical fiber A station S A is connected to one end 1
The other end of 3 is a 1 × M (M ≧ 2) type optical star coupler 17
Port end P 0 of being connected, B station S B to N stations S N is connected to the M port end P 1 to P m of the optical star coupler 17. At the stations B B to S N , the optical transmitter 15
-1 to 15-m and optical receivers 14-1 to 14-m are connected to optical multiplexer / demultiplexers 12-2 to 12-n via isolators 10-2 to 10-n and 11-2 to 11-n. Are connected to the input terminal and the output terminal of the optical multiplexer / demultiplexer 12-2 to 12-n, respectively.
Are the port ends P 1 to P m of the optical star coupler 17.
Connected to each other.
【００５７】このようなシステムにおいて、Ａ局ＳA の
光送信機１５が作動すると、波長λ1 の信号光が矢印１
−１方向に伝搬し、光アイソレータ１０−１を通って光
増幅器Ａ１のＥｒ添加光ファイバ８で増幅される。増幅
された波長λ1 の信号光は矢印１−４方向に伝搬し、光
合分波器１２−１の入力端１２−１ａに入力される。光
合分波器１２−１を通って矢印１−５方向に伝搬する波
長λ1 の信号光は光ファイバ１３に入力される。波長λ
1 の信号光は光ファイバ１３を矢印１−５、１−６方向
に伝搬し光スターカプラ１７のポート端Ｐ0 に入力され
る。光スターカプラ１７に入力した波長λ1 の信号光は
ｍ分岐されてＢ局ＳB 〜Ｎ局ＳN の光合分波器１２−２
〜１２−ｎを通って各受信機１４−１〜１４−ｍに同時
に伝搬される。[0057] In such a system, the optical transmitter 15 of the station A S A is activated, the wavelength lambda 1 of the signal light arrow 1
The light propagates in the -1 direction, passes through the optical isolator 10-1, and is amplified by the Er-doped optical fiber 8 of the optical amplifier A1. The amplified signal light of wavelength λ 1 propagates in the direction of arrow 1-4 and is input to the input terminal 12-1a of the optical multiplexer / demultiplexer 12-1. The signal light of wavelength λ 1 propagating in the direction of arrow 1-5 through the optical multiplexer / demultiplexer 12-1 is input to the optical fiber 13. Wavelength λ
1 of the signal light is input to the port terminal P 0 of the optical star coupler 17 propagates through the optical fiber 13 in the arrow 1-5 and 1-6 directions. Optical star signal light having a wavelength lambda 1 input to the coupler 17 are m branching B station S B to N stations S N of the optical demultiplexer 12-2
-12-n to the respective receivers 14-1 to 14-m at the same time.
【００５８】一方、Ｂ局ＳB 〜Ｎ局ＳN の各光送信機１
５−１〜１５−ｍが作動すると、波長λ2 の信号光が光
アイソレータ１１−２〜１１−ｎを通って光合分波器１
２−２〜１２−ｎにそれぞれ入力され、光スターカプラ
１７の各ポート端Ｐ1 〜Ｐmに入力される。光スターカ
プラ１７に入力された波長λ2 の信号光は光ファイバ１
３を矢印２−２、２−３方向に伝搬し、Ａ局ＳA の光合
分波器１２−１に入力し分波されて光増幅器Ａ２のＰｒ
添加光ファイバ９で増幅された後光アイソレータ１１−
１を通って光受信機１４で受信される。Meanwhile, the optical transmitter of station B S B to N station S N 1
When 5-1 to 15-m operates, the signal light of the wavelength λ 2 passes through the optical isolators 11-2 to 11-n and the optical multiplexer / demultiplexer 1
Are input to the 2-2~12-n, input to each port end P 1 to P m of the optical star coupler 17. The signal light of wavelength λ 2 input to the optical star coupler 17 is
3 was propagated in the arrow 2-2 and 2-3 directions, and input to the optical demultiplexer 12-1 of station A S A demultiplexed has been Pr of the optical amplifier A2
After being amplified by the added optical fiber 9, the optical isolator 11-
1 and received by the optical receiver 14.
【００５９】以上において、加入者の数が複数の場合に
も光スターカプラを用いることにより対応することがで
き、加入者数が増加してもポート数の大きな光スターカ
プラに交換するか他のスターカプラを挿入することによ
り対応することができる。In the above description, it is possible to cope with the case where the number of subscribers is plural by using the optical star coupler. This can be achieved by inserting a star coupler.
【００６０】また、Ａ局ＳA において光送信機１５から
の信号光が増幅された後Ｂ局ＳB 〜Ｎ局ＳN に伝搬さ
れ、Ｂ局ＳB 〜Ｎ局ＳN からの信号光がＡ局ＳA におい
て増幅されるので、光ファイバ１３の長さを延長するこ
とができる。[0060] Moreover, it is propagated to the B station S B to N stations S N after the signal light from the optical transmitter 15 is amplified in A station S A, the signal light from the B station S B to N stations S N is since the amplified in a station S a, it is possible to extend the length of the optical fiber 13.
【００６１】しかも、Ａ局ＳA 及びＢ局ＳB 〜Ｎ局ＳN
において、光送信機１５、１５−１〜１５−ｍの出力側
と光受信機１４、１４−１〜１４−ｍの入力側にそれぞ
れ光アイソレータ１０−１〜１０−ｎ、１１−１〜１１
−ｎが接続されているので、クロストーク特性に優れた
双方向増幅伝送を実現することができる。尚、光スター
カプラ１７ではポート端Ｐ1 〜Ｐm の数Ｍに応じた分岐
損失を伴うが、いずれの波長λ1 ，λ2 の信号光も十分
に増幅されて伝送されるので、増幅率の高い光増幅器を
用いることにより分岐損失を補うことができる。In addition, the A station S A and the B station S B to the N station S N
, Optical isolators 10-1 to 10-n and 11-1 to 11-n on the output side of optical transmitters 15 and 15-1 to 15-m and on the input side of optical receivers 14 and 14-1 to 14-m, respectively.
Since -n is connected, bidirectional amplification transmission excellent in crosstalk characteristics can be realized. Although the optical star coupler 17 has a branch loss corresponding to the number M of the port ends P 1 to P m , the signal light of any of the wavelengths λ 1 and λ 2 is sufficiently amplified and transmitted. The branch loss can be compensated for by using an optical amplifier having a high level.
【００６２】図４は本発明の双方向増幅伝送方法を適用
した双方向増幅伝送システムの他の実施の形態を示すブ
ロック図である。FIG. 4 is a block diagram showing another embodiment of the bidirectional amplification transmission system to which the bidirectional amplification transmission method of the present invention is applied.
【００６３】図３に示した双方向増幅伝送システムとの
相違点は、Ａ局側の光増幅器が光ファイバと光合分波器
との間に設けられている点である。The difference from the bidirectional amplification transmission system shown in FIG. 3 is that the optical amplifier on the side of the station A is provided between the optical fiber and the optical multiplexer / demultiplexer.
【００６４】図３に示したシステムと同様に、Ａ局ＳA
の光送信機１５から発生した波長λ 1 の信号光が光アイ
ソレータ１０−１及び光合分波器１２−１を通って光増
幅器Ａ１に入力されて増幅され、光増幅器Ａ２、光ファ
イバ１３及び光スターカプラ１７を介してＢ局ＳB 〜Ｎ
局ＳN の光合分波器１２−２〜１２−ｎ、光アイソレー
タ１０−２〜１０−ｎを通って光受信機１４−１〜１４
−ｍで受信される。As in the system shown in FIG.A
Wavelength λ generated from the optical transmitter 15 1Signal light is optical eye
The light increases through the solator 10-1 and the optical multiplexer / demultiplexer 12-1.
The optical amplifier A2 is input to the amplifier A1 and amplified.
B station S via Iva 13 and optical star coupler 17B~ N
Station SNOptical multiplexer / demultiplexer 12-2 to 12-n, optical isolator
Optical receivers 14-1 through 14-n
-M.
【００６５】Ｂ局ＳB 〜Ｎ局ＳN の各光送信機１５−１
〜１５−ｍから発生した波長λ2 の信号光が光アイソレ
ータ１１−２〜１１−ｍ、光合分波器１２−２〜１２−
ｎ、光スターカプラ１７及び光ファイバ１３を通ってＡ
局ＳA の光増幅器Ａ２に入力されて増幅され、光増幅器
Ａ１、光合分波器１２−１及び光アイソレータ１１−１
を通って光受信機１４で受信される。[0065] B station S B to N stations each optical transmitter S N 15-1
Signal light of wavelength [lambda] 2 generated from .about.15-m is divided into optical isolators 11-2 to 11-m and optical multiplexer / demultiplexers 12-2 to 12-.
n, A through the optical star coupler 17 and the optical fiber 13
Is inputted is amplified in the optical amplifier A2 of the station S A, the optical amplifier A1, the optical demultiplexer 12-1 and the optical isolator 11-1
Through the optical receiver 14.
【００６６】以上において、図３に示した双方向増幅伝
送システムと同様に、伝送距離が長く、加入者数の増加
に対応でき、しかもクロストーク特性に優れた双方向増
幅伝送を実現することができる。As described above, similarly to the bidirectional amplification transmission system shown in FIG. 3, it is possible to realize a bidirectional amplification transmission that has a long transmission distance, can cope with an increase in the number of subscribers, and has excellent crosstalk characteristics. it can.
【００６７】図５は本発明の双方向増幅伝送方法を適用
した双方向増幅伝送システムの他の実施の形態を示すブ
ロック図である。FIG. 5 is a block diagram showing another embodiment of the bidirectional amplification transmission system to which the bidirectional amplification transmission method of the present invention is applied.
【００６８】図４に示した双方向増幅伝送システムとの
相違点は、Ａ局側において光受信機と光アイソレータと
の間にチューナブルフィルタを設けた点である。The difference from the bidirectional amplification transmission system shown in FIG. 4 is that a tunable filter is provided between the optical receiver and the optical isolator on the A station side.
【００６９】Ａ局ＳA の光送信機１５が作動すると、波
長λ1 （１．３μｍ帯）の信号光が矢印１−１方向に伝
搬して光アイソレータ１０−１を通って光増幅器Ａ１で
増幅され、ＷＤＭカプラ７−２を通って光合分波器１２
−１に入力される。増幅された波長λ1 の信号光は光フ
ァイバ１３を伝搬し光スターカプラ１７のポート端Ｐ0
に入力される。光スターカプラ１７に入力した波長λ1
の信号光はｍ分岐されてＢ局ＳB 〜Ｎ局ＳN の光合分波
器１２−２〜１２−ｎを通って各受信機１４−１〜１４
−ｍに同時に伝搬される。[0069] In A station when the optical transmitter 15 of the S A is activated, the optical amplifier A1 through the optical isolator 10-1 signal light of the wavelength lambda 1 (1.3 .mu.m band) propagates in an arrow 1-1 direction Amplified and passed through the WDM coupler 7-2, the optical multiplexer / demultiplexer 12
-1 is input. The amplified signal light having the wavelength λ 1 propagates through the optical fiber 13 and is transmitted to the port P 0 of the optical star coupler 17.
Is input to The wavelength λ 1 input to the optical star coupler 17
Of the signal light is m branch has been B station S B to N stations S N of the optical demultiplexer through 12-2~12-n each receiver 14-1 to 14
-M simultaneously.
【００７０】Ｂ局ＳB 〜Ｎ局ＳN の各光送信機１５−１
〜１５−ｍが作動すると、波長１．５５μｍ帯の異なる
波長の信号光（例えば１．５３μｍから１．５６μｍの
範囲の信号光）が光アイソレータ１１−２〜１１−ｎを
通って光スターカプラ１７の各ポート端Ｐ1 〜Ｐm に入
力される。光スターカプラ１７に入力された異なる波長
の信号光は光ファイバ１３を矢印２−２、２−３方向に
伝搬し、Ａ局ＳA の光合分波器１２−１に入力し分波さ
れて光増幅器Ａ２のＰｒ添加光ファイバ９で増幅された
後光アイソレータ１１−１を通ってチューナブルフィル
タ１８で所望の波長の信号光のみ通過されて光受信機１
４で受信される。Each of the optical transmitters 15-1 of the stations B to N.
〜15-m operates, signal light of a different wavelength in the 1.55 μm band (for example, signal light in the range of 1.53 μm to 1.56 μm) passes through the optical isolators 11-2 to 11-n to form an optical star coupler. input to each port end P 1 to P m of 17. Signal light having different wavelengths input to the optical star coupler 17 propagates through the optical fiber 13 in the arrow 2-2 and 2-3 directions, are demultiplexed input to the optical demultiplexer 12-1 of station A S A After being amplified by the Pr-doped optical fiber 9 of the optical amplifier A2, it passes through the optical isolator 11-1 and passes only the signal light of the desired wavelength through the tunable filter 18 so that the optical receiver 1
4 is received.
【００７１】以上チューナブルフィルタ１８を有するシ
ステムにおいても、伝送距離が長く、加入者数の増加に
対応でき、しかもクロストーク特性に優れた双方向増幅
伝送を実現することができる。As described above, even in the system having the tunable filter 18, the transmission distance is long, the number of subscribers can be increased, and bidirectional amplification transmission excellent in crosstalk characteristics can be realized.
【００７２】図６は本発明の双方向増幅伝送方法を適用
した双方向増幅伝送システムの他の実施の形態を示すブ
ロック図である。FIG. 6 is a block diagram showing another embodiment of the bidirectional amplification transmission system to which the bidirectional amplification transmission method of the present invention is applied.
【００７３】図５に示した双方向増幅伝送システムとの
相違点は、Ａ局側において光ファイバと光合分波器との
間に光増幅器が設けられている点である。The difference from the bidirectional amplification transmission system shown in FIG. 5 is that an optical amplifier is provided between the optical fiber and the optical multiplexer / demultiplexer on the A station side.
【００７４】図５に示した双方向増幅伝送システムと同
様に、Ａ局ＳA の光送信機１５で発生した波長λ
1 （１．３μｍ帯）の信号光が、光アイソレータ１０−
１、光合分波器１２−１、光増幅器Ａ１，Ａ２、光ファ
イバ１３及び光スターカプラ１７を介してＢ局ＳB 〜Ｎ
局ＳN に伝搬し、Ｂ局ＳB 〜Ｎ局ＳN の光送信機１５−
１〜１５−ｍで発生した波長１．５５μｍ帯の異なる波
長の信号光が光アイソレータ１１−２〜１１−ｎ、光ス
ターカプラ１７及び光ファイバ１３を介してＡ局ＳAに
伝搬した後、Ａ局ＳA のチューナブルフィルタ１８で波
長の異なる信号光を選択的に受信することにより、伝送
距離を長くすることができ、加入者数の増加に対応で
き、しかもクロストーク特性に優れた双方向増幅伝送を
実現することができる。[0074] Similar to the bidirectional amplifier transmission system shown in FIG. 5, the wavelength generated by the light transmitter 15 of the station A S A lambda
1 (1.3 μm band) signal light is
1. Stations B B to N via optical multiplexer / demultiplexer 12-1, optical amplifiers A1 and A2, optical fiber 13, and optical star coupler 17.
Propagates to the station S N, B station S B to N stations S N of the optical transmitter 15
After the signal light of different wavelengths in wavelength 1.55μm band generated in 1 to 15-m is propagated to the A station S A through the optical isolator 11-2 to 11-n, optical star coupler 17 and optical fiber 13, both by selectively receive different signal light wavelengths in the tunable filter 18 of the a station S a, it is possible to increase the transmission distance, can accommodate the increased number of subscribers, yet with excellent crosstalk characteristic Amplified transmission can be realized.
【００７５】以上において本発明によれば、 (1) 一本の光ファイバ内を逆方向に伝搬する波長の異な
る信号光を、長距離伝送することができると共に、信号
光間のクロストーク特性も良好で信号光の反射光や増幅
された信号光の反射光の漏れ込みによるクロストークの
劣化も抑圧でき、しかも反射戻り光による信号光の光源
の波長変動や出力変動を防止することができる。As described above, according to the present invention, (1) signal lights having different wavelengths propagating in the opposite direction in one optical fiber can be transmitted over a long distance, and the crosstalk characteristics between the signal lights can be improved. It is possible to suppress the deterioration of crosstalk due to leakage of the reflected light of the signal light or the amplified signal light, and to prevent the fluctuation of the wavelength and the output of the signal light source due to the reflected return light.
【００７６】(2) システムの拡張が容易である。(2) The system can be easily expanded.
【００７７】(3) 長期的に安定で受信エラーの少ないシ
ステムを構築することができる。(3) It is possible to construct a system that is stable for a long time and has few reception errors.
【００７８】(4) 低損失な光部品で構成することができ
るので、より長距離に低雑音指数特性で伝送することが
できる。(4) Since it can be composed of low-loss optical components, it can be transmitted over a longer distance with low noise figure characteristics.
【００７９】尚、図１〜図６に示した双方向増幅伝送シ
ステムは、Ｅｒ添加光ファイバ或いはＰｒ添加光ファイ
バへの励起方法が同一方向励起方法を用いたが、双方向
励起方法を用いてもよい。また、図４においてＥｒ添加
光ファイバ８とＰｒ添加光ファイバとをカスケード接続
しているが、ＥｒとＰｒとを共添加した光ファイバを用
いてもよい。In the bidirectional amplification transmission systems shown in FIGS. 1 to 6, the pumping method for the Er-doped optical fiber or the Pr-doped optical fiber uses the same-directional pumping method. Is also good. Although the Er-doped optical fiber 8 and the Pr-doped optical fiber are cascaded in FIG. 4, an optical fiber in which Er and Pr are co-doped may be used.
【００８０】[0080]
【発明の効果】以上要するに本発明によれば、次のよう
な優れた効果を発揮する。In summary, according to the present invention, the following excellent effects are exhibited.
【００８１】(1) 一方の光通信局において光送信機で発
生した信号光を光増幅器で増幅した後一本の光伝送路を
介して他方の光通信局に送信すると共に、他方の光通信
局から光伝送路を介して送信された信号光を一方の光通
信局において光増幅器で増幅した後受信することによ
り、伝送距離が長い双方向増幅伝送方法の提供を実現す
ることができる。(1) In one optical communication station, the signal light generated by the optical transmitter is amplified by an optical amplifier and then transmitted to the other optical communication station via one optical transmission line, while the other optical communication station By receiving the signal light transmitted from the station via the optical transmission line after being amplified by the optical amplifier in one of the optical communication stations, it is possible to realize the provision of a bidirectional amplification transmission method having a long transmission distance.
【００８２】(2) 光送信機及び光受信機に光アイソレー
タを設けることにより、クロストーク特性の劣化を防止
した双方向増幅伝送方法の提供を実現することができ
る。(2) By providing the optical transmitter and the optical receiver with the optical isolator, it is possible to realize the provision of the bidirectional amplification transmission method in which the deterioration of the crosstalk characteristic is prevented.
【００８３】(3) 一方の光通信局と、他方のＭ箇所の光
通信局とを一本の光伝送路及び１×Ｍ型光スターカプラ
で接続することにより加入者数の増加に対応できる双方
向増幅伝送方法の提供を実現することができる。(3) By connecting one optical communication station and the other M optical communication stations with one optical transmission line and a 1 × M-type optical star coupler, it is possible to cope with an increase in the number of subscribers. Provision of a bidirectional amplification transmission method can be realized.
【図１】本発明の双方向増幅伝送方法を適用した双方向
増幅伝送システムの一実施の形態を示すブロック図であ
る。FIG. 1 is a block diagram showing an embodiment of a bidirectional amplification transmission system to which a bidirectional amplification transmission method of the present invention is applied.
【図２】本発明の双方向増幅伝送方法を適用した双方向
増幅伝送システムの他の実施の形態を示すブロック図で
ある。FIG. 2 is a block diagram showing another embodiment of a bidirectional amplification transmission system to which the bidirectional amplification transmission method of the present invention is applied.
【図３】本発明の双方向増幅伝送方法を適用した双方向
増幅伝送システムの他の実施の形態を示すブロック図で
ある。FIG. 3 is a block diagram showing another embodiment of the bidirectional amplification transmission system to which the bidirectional amplification transmission method of the present invention is applied.
【図４】本発明の双方向増幅伝送方法を適用した双方向
増幅伝送システムの他の実施の形態を示すブロック図で
ある。FIG. 4 is a block diagram showing another embodiment of the bidirectional amplification transmission system to which the bidirectional amplification transmission method of the present invention is applied.
【図５】本発明の双方向増幅伝送方法を適用した双方向
増幅伝送システムの他の実施の形態を示すブロック図で
ある。FIG. 5 is a block diagram showing another embodiment of the bidirectional amplification transmission system to which the bidirectional amplification transmission method of the present invention is applied.
【図６】本発明の双方向増幅伝送方法を適用した双方向
増幅伝送システムの他の実施の形態を示すブロック図で
ある。FIG. 6 is a block diagram showing another embodiment of the bidirectional amplification transmission system to which the bidirectional amplification transmission method of the present invention is applied.
【図７】双方向伝送方法の従来例のブロック図である。FIG. 7 is a block diagram of a conventional example of a bidirectional transmission method.
１０−１，１０−２，１１−１，１１−２ 光アイソレ
ータ １２−１，１２−２ 光合分波器 １３ 光伝送路（光ファイバ） １４，１４−１ 光受信機 １５，１５−１ 光送信機 １７ １×Ｍ型光スターカプラ10-1, 10-2, 11-1, 11-2 Optical isolator 12-1, 12-2 Optical multiplexer / demultiplexer 13 Optical transmission line (optical fiber) 14, 14-1 Optical receiver 15, 15-1 Optical Transmitter 17 1 × M type optical star coupler
Claims (8)
本の光伝送路で接続し、該光伝送路内に少なくとも二つ
の波長の異なる信号光を双方向に伝送する双方向伝送方
法において、一方の光通信局は光送信機、光受信機、第
１の波長用光増幅器、第２の波長用光増幅器及び光合分
波器を有すると共に、他方の光通信局は光送信機、光受
信機及び光合分波器を有し、一方の光通信局は一方の光
送信機から第１の波長の信号光を第１の波長用の光増幅
器、一方の光合分波器、光伝送路及び他方の光合分波器
を介して他方の光受信機に送信し、他方の光通信局は他
方の光送信機から第２の波長の信号光を他方の光合分波
器、光伝送路、一方の光合分波器、第２の波長用光増幅
器を介して一方の光受信機に送信することを特徴とする
双方向増幅伝送方法。1. An optical communication station in which one optical communication station and the other optical communication station are connected by one optical transmission line, and at least two signal lights having different wavelengths are transmitted bidirectionally in the optical transmission line. In the transmission method, one optical communication station has an optical transmitter, an optical receiver, an optical amplifier for a first wavelength, an optical amplifier for a second wavelength, and an optical multiplexer / demultiplexer, and the other optical communication station has an optical transmission Device, an optical receiver, and an optical multiplexer / demultiplexer, and one optical communication station transmits the signal light of the first wavelength from the one optical transmitter to an optical amplifier for the first wavelength, one optical multiplexer / demultiplexer, The signal is transmitted to the other optical receiver via the optical transmission line and the other optical multiplexer / demultiplexer, and the other optical communication station transmits the signal light of the second wavelength from the other optical transmitter to the other optical multiplexer / demultiplexer. A bidirectional amplification transmission method comprising transmitting to one optical receiver via a transmission line, one optical multiplexer / demultiplexer, and a second wavelength optical amplifier. .
増幅器にカスケード接続された第１の波長用光アイソレ
ータを有し、一方の光送信機からの信号光を第１の波長
用光アイソレータを介して第１の波長用光増幅器で増幅
した後光合波器及び光伝送路を介して他方の光通信局へ
送信する請求項１に記載の双方向増幅伝送方法。2. The optical communication station according to claim 1, further comprising: a first wavelength optical isolator cascaded to the first wavelength optical amplifier, and transmitting the signal light from the one optical transmitter to the first wavelength optical amplifier. 2. The bidirectional amplification transmission method according to claim 1, wherein the signal is amplified by a first wavelength optical amplifier via an optical isolator and then transmitted to the other optical communication station via an optical multiplexer and an optical transmission line.
増幅器にカスケード接続された第２の波長用光アイソレ
ータを有し、他方の光通信局からの信号光を第２の波長
用光アイソレータを介して第２の波長用光増幅器で増幅
した後一方の光受信機で受信する請求項１に記載の双方
向増幅伝送方法。3. The one optical communication station has a second wavelength optical isolator cascaded to a second wavelength optical amplifier, and transmits a signal light from the other optical communication station to a second wavelength optical amplifier. 2. The bidirectional amplification transmission method according to claim 1, wherein the signal is amplified by a second wavelength optical amplifier via a second optical isolator and then received by one of the optical receivers.
信局とを一本の光伝送路及び１×Ｍ型光スターカプラで
接続し、上記光伝送路内に少なくとも二つの波長の異な
る信号光を双方向に伝送する双方向伝送方法において、
一方の光通信局は光送信機、光受信機、第１の波長用光
増幅器、第２の波長用光増幅器及び光合分波器を有する
と共に、他方の光通信局は光送信機、光受信機及び光合
分波器をそれぞれ有し、一方の光通信局は一方の光送信
機から第１の波長の信号光を第１の波長用の光増幅器、
一方の光合分波器、光伝送路、１×Ｍ型光スターカプラ
及び他方の光合分波器を介して他方の光受信機に送信
し、他方の光通信局は他方の光送信機から第２の波長の
信号光を他方の光合分波器、１×Ｍ型光スターカプラ、
光伝送路、一方の光合分波器、第２の波長用光増幅器を
介して一方の光受信機に送信することを特徴とする双方
向増幅伝送方法。4. One optical communication station and the other M optical communication stations are connected by one optical transmission line and a 1 × M-type optical star coupler, and at least two wavelengths are provided in the optical transmission line. In a two-way transmission method for transmitting two different signal lights in two directions,
One optical communication station has an optical transmitter, an optical receiver, an optical amplifier for a first wavelength, an optical amplifier for a second wavelength, and an optical multiplexer / demultiplexer, and the other optical communication station has an optical transmitter, an optical receiver, And an optical multiplexer / demultiplexer, and one optical communication station converts the signal light of the first wavelength from the one optical transmitter into an optical amplifier for the first wavelength,
The signal is transmitted to the other optical receiver via one optical multiplexer / demultiplexer, an optical transmission line, a 1 × M-type optical star coupler, and the other optical multiplexer / demultiplexer. A signal light having a wavelength of 2 to the other optical multiplexer / demultiplexer, a 1 × M-type optical star coupler,
A two-way amplification transmission method, wherein the signal is transmitted to one optical receiver via an optical transmission line, one optical multiplexer / demultiplexer, and a second wavelength optical amplifier.
増幅器にカスケード接続された第１の波長用光アイソレ
ータを有し、一方の光送信機からの信号光を第１の波長
用光アイソレータを介して第１の波長用光増幅器で増幅
した後光合波器及び光伝送路を介して他方の光通信局へ
送信する請求項４に記載の双方向増幅伝送方法。5. The one optical communication station has a first wavelength optical isolator cascade-connected to a first wavelength optical amplifier, and transmits the signal light from one optical transmitter to the first wavelength optical amplifier. The two-way amplification transmission method according to claim 4, wherein the signal is amplified by the first wavelength optical amplifier via the optical isolator and then transmitted to the other optical communication station via the optical multiplexer and the optical transmission line.
増幅器にカスケード接続された第２の波長用光アイソレ
ータを有し、他方の光通信局からの信号光を第２の波長
用光アイソレータを介して第２の波長用光増幅器で増幅
した後一方の光受信機で受信する双方向増幅伝送方法。6. The one optical communication station has a second wavelength optical isolator cascaded to a second wavelength optical amplifier, and transmits the signal light from the other optical communication station to the second wavelength optical amplifier. Bidirectional amplification transmission method in which the signal is amplified by the second wavelength optical amplifier via the optical isolator and then received by one of the optical receivers.
り、上記第２の波長が１．３μｍ帯であるか又は第１の
波長が１．３μｍ帯であり、上記第２の波長が１．５５
μｍ帯である請求項１から６のいずれかに記載の双方向
増幅伝送方法。7. The first wavelength is in a 1.55 μm band, the second wavelength is in a 1.3 μm band, or the first wavelength is in a 1.3 μm band, and the second wavelength is in a 1.3 μm band. 1.55
The bidirectional amplification transmission method according to any one of claims 1 to 6, wherein the transmission frequency is in the μm band.
信局とを一本の光伝送路及び１×Ｍ型光スターカプラで
接続し、上記光伝送路内に少なくとも二つの波長の異な
る信号光を双方向に伝送する双方向伝送方法において、
一方の光通信局は光送信機、光受信機、第１の波長用光
増幅器、第２の波長用光増幅器及び光合分波器を有する
と共に、他方の光通信局は光送信機、光受信機及び光合
分波器をそれぞれ有し、一方の光通信局は一方の光送信
機から第１の波長の信号光を第１の波長用の光増幅器、
一方の光合分波器、光伝送路、１×Ｍ型光スターカプラ
及び他方の光合分波器を介して他方の光受信機に送信
し、他方の各光通信局は他方の各光送信機から第２の波
長を含む波長帯の信号光のうち波長帯をＭ分配して異な
らせた信号光を、他方の光合分波器、１×Ｍ型光スター
カプラ、光伝送路を介して、一方の光通信局へ送信する
と共に、一方の光通信局では光受信機と光合分波器との
間に設けられたチューナブル光フィルタによって上記波
長帯の信号光をチューニングして選択的に受信する双方
向増幅伝送方法。8. One optical communication station and another M optical communication stations are connected by one optical transmission line and a 1 × M-type optical star coupler, and at least two wavelengths are provided in the optical transmission line. In a two-way transmission method for transmitting two different signal lights in two directions,
One optical communication station has an optical transmitter, an optical receiver, an optical amplifier for a first wavelength, an optical amplifier for a second wavelength, and an optical multiplexer / demultiplexer, and the other optical communication station has an optical transmitter, an optical receiver, And an optical multiplexer / demultiplexer, and one optical communication station converts the signal light of the first wavelength from the one optical transmitter into an optical amplifier for the first wavelength,
The signal is transmitted to the other optical receiver via one optical multiplexer / demultiplexer, an optical transmission line, a 1 × M-type optical star coupler and the other optical multiplexer / demultiplexer, and each of the other optical communication stations is transmitted to the other optical transmitter. From the signal light in the wavelength band including the second wavelength, the signal light obtained by distributing the wavelength band to M and differing from each other is passed through the other optical multiplexer / demultiplexer, the 1 × M-type optical star coupler, and the optical transmission line, While transmitting to one optical communication station, one optical communication station tunes the signal light in the above wavelength band by a tunable optical filter provided between the optical receiver and the optical multiplexer / demultiplexer, and selectively receives it. Bidirectional amplification transmission method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8316197A JPH10163978A (en) | 1996-11-27 | 1996-11-27 | Bidirectional amplification/transmission method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8316197A JPH10163978A (en) | 1996-11-27 | 1996-11-27 | Bidirectional amplification/transmission method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH10163978A true JPH10163978A (en) | 1998-06-19 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8316197A Pending JPH10163978A (en) | 1996-11-27 | 1996-11-27 | Bidirectional amplification/transmission method |
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| Country | Link |
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| JP (1) | JPH10163978A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004180202A (en) * | 2002-11-29 | 2004-06-24 | Synclayer Inc | Transmission system of optical fiber network system, optical network system thereof, and terminal equipment thereof |
| KR100450748B1 (en) * | 2001-12-27 | 2004-10-01 | 한국전자통신연구원 | Bi-directional optical transmitter with stimulated brillouin amplification and method thereof |
| JP2007006341A (en) * | 2005-06-27 | 2007-01-11 | Chugoku Electric Power Co Inc:The | Channel assignment method for optical network |
| JP2007006340A (en) * | 2005-06-27 | 2007-01-11 | Chugoku Electric Power Co Inc:The | Optical transmission system adopting pon |
-
1996
- 1996-11-27 JP JP8316197A patent/JPH10163978A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100450748B1 (en) * | 2001-12-27 | 2004-10-01 | 한국전자통신연구원 | Bi-directional optical transmitter with stimulated brillouin amplification and method thereof |
| JP2004180202A (en) * | 2002-11-29 | 2004-06-24 | Synclayer Inc | Transmission system of optical fiber network system, optical network system thereof, and terminal equipment thereof |
| JP2007006341A (en) * | 2005-06-27 | 2007-01-11 | Chugoku Electric Power Co Inc:The | Channel assignment method for optical network |
| JP2007006340A (en) * | 2005-06-27 | 2007-01-11 | Chugoku Electric Power Co Inc:The | Optical transmission system adopting pon |
| JP4519014B2 (en) * | 2005-06-27 | 2010-08-04 | 中国電力株式会社 | Channel assignment method for optical network |
| JP4519013B2 (en) * | 2005-06-27 | 2010-08-04 | 中国電力株式会社 | PON optical transmission system |
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