JPS60163544A

JPS60163544A - Optical communication equipment

Info

Publication number: JPS60163544A
Application number: JP59018693A
Authority: JP
Inventors: Osamu Kato; 修加藤; Yutaka Miura; 裕三浦; Takao Funahashi; 鮒橋　隆夫
Original assignee: Matsushita Electric Industrial Co Ltd
Current assignee: Panasonic Holdings Corp
Priority date: 1984-02-03
Filing date: 1984-02-03
Publication date: 1985-08-26

Abstract

PURPOSE:To bring an optical power received by a receiver by connecting prescribed two terminals of an optical switch and receiving an output light of an optical branching device at the receiver in conducting a reflecting test of a transmitter. CONSTITUTION:An optical signal transmitted from an optical transmitter 9 of a point A is divided into a signal transmitted to an optical transmission line 4 through an optical branching synthesizer 5 via an optical branching device 11 and a signal transmitted to an input terminal (f) of an optical switch 12. Then the light transmitted to the transmission line 4 is branched by an optical branching synthesizer 3 at a point B and received by an optical receiver 1. On the other hand, the optical signal transmitted from an optical transmitter 2 of the point B is transmitted to the transmission line 4 by the synthesizer 3, branched by a synthesizer 5 of the point A and fed to an input terminal (e) of the switch 12. Terminals e, d of the switch 12 are connected normally and the transmitted optical signal is received by an optical receiver 8. In conducting the reflecting test of the transmitter 9, terminals f, d of the switch 12 are connected and the output light from a terminal (c) of the branching filter 11 is received by the receiver 8.

Description

【発明の詳細な説明】産業上の利用分野本発明は、双方向光通信の送信部での折り返し試験を実
現するだめの折り返し試験用光回路を具備した光通信装
置に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical communication device equipped with an optical circuit for a loopback test for realizing a loopback test at a transmitting section of bidirectional optical communication.

従来例の構成とその問題点第１図は従来の折り返し試験用光回路を具備した光通信
装置を示している。以下にこの従来例の構成について第
１図とともに説明する。第１図において、９はＡ地点に
ある光送信器であり、ここから送信された光信号は５の
光分波合波器により４の光伝送路へと送られる。そして
Ｂ地点に至り３の光分波合波器で分波され、１の光受信
器で受信される。一方、２はＢ地点にある光送信器であ
シ、ここから送信された光信号は３の光分波合波器によ
り４の光伝送路へと送られる。そしてＡ地点に至り５の
光分波合波器で分波され、８の光受信器で受信される。Structure of a conventional example and its problems FIG. 1 shows an optical communication device equipped with a conventional folding test optical circuit. The configuration of this conventional example will be explained below with reference to FIG. 1. In FIG. 1, numeral 9 is an optical transmitter located at point A, and the optical signal transmitted from this transmitter is sent to an optical transmission line 4 by an optical demultiplexer/multiplexer 5. The light then reaches point B, where it is demultiplexed by three optical demultiplexers and multiplexers, and received by one optical receiver. On the other hand, 2 is an optical transmitter located at point B, and the optical signal transmitted from this is sent to an optical transmission line 4 by an optical demultiplexer/multiplexer 3. The light then reaches point A, is demultiplexed by optical demultiplexer/multiplexer 5, and received by optical receiver 8.

６および７は光スィッチであり、スイッチの切替えによ
って通常の双方向光通信状態と、９の光送信器の動作を
確認するための折シ返し試験状態とを切替えることがで
きる。6 and 7 are optical switches, and by switching the switches, it is possible to switch between a normal two-way optical communication state and a return test state for checking the operation of the optical transmitter 9.

次に上記従来例の動作について説明する。第１図におい
て、双方向光通信を行う場合には、光スィッチ６の端子
ａと端子すおよび、光スィッチ７の端子ｅと端子ｄを接
続する。これにより９の光送信器から出だ光信号は５の
光分波合波器へと送られ、またＢ地点からＡ地点へ向か
って送られてきた光信号は５の光分波合波器で分波され
、８の光受信器へと送られる。このようにして双方向光
通信が可能となる。Next, the operation of the above conventional example will be explained. In FIG. 1, when performing bidirectional optical communication, terminals a and d of optical switch 6 are connected, and terminals e and d of optical switch 7 are connected. As a result, the optical signal output from the optical transmitter 9 is sent to the optical demultiplexer/multiplexer 5, and the optical signal sent from point B to point A is sent to the optical demultiplexer/multiplexer 5. The signal is demultiplexed and sent to optical receiver 8. In this way, bidirectional optical communication becomes possible.

一方、９の送信器部の動作を確認するだめの折り返し試
験を行う場合には、光スィッチ６の端子ａと端子Ｃおよ
び光スィッチ７の端子ｆと端子ｄを接続する。これによ
り９の光送信器から出た光信号は２つの光スィッチを通
って８の光受信器へと送られることになり、折り返し試
験が可能となる０しかしながら、上記従来例においては次のような欠点が
あった。On the other hand, when conducting a return test to confirm the operation of the transmitter section 9, terminals a and C of the optical switch 6 and terminals f and d of the optical switch 7 are connected. As a result, the optical signal output from the optical transmitter 9 passes through two optical switches and is sent to the optical receiver 8, making it possible to perform a loop test.0 However, in the conventional example above, the following There was a drawback.

（１）光スィッチ６の端子ａでの反射光が９の光送信部
に戻る割合を、送信部における劣化を生じない程度に抑
えることが困難である。(1) It is difficult to suppress the rate at which the light reflected at the terminal a of the optical switch 6 returns to the optical transmitter 9 to a level that does not cause deterioration in the transmitter.

（２）折り返し試験を行う場合に、９の光送信部から出
だ光が２つの光スィッチだけを通って８の受信器にはい
るために受信器の受光レベルが過大になってしまい、こ
れを防ぐためには例えば光スイン６の端子Ｃと光スィッ
チ７の端子ｆの間に光減衰器を挿入する必要がある。(2) When performing a loopback test, the light emitted from the optical transmitter 9 passes through only two optical switches and enters the receiver 8, resulting in an excessive light receiving level at the receiver. In order to prevent this, it is necessary to insert an optical attenuator between the terminal C of the optical switch 6 and the terminal f of the optical switch 7, for example.

（３）光スィッチは光分岐器に比べて挿入損失が大きい
、高価である１寸法が大きいという欠点がある。(3) Compared to optical splitters, optical switches have disadvantages such as higher insertion loss, higher cost, and larger dimensions.

（４）光スィッチは一般にはプリズム等を機械的に駆動
して光路を切替えているだめに信頼性の点で光分岐器よ
りも劣る。(4) Since an optical switch generally switches the optical path by mechanically driving a prism or the like, it is inferior to an optical splitter in terms of reliability.

第２図は、他の従来例を示している。Ａ地点における光
スィッチの構成が第１図の場合と異なる点を除いては、
第１図と同じである。第２図において、双方向光通信を
行う場合には、光スィッチ１０の端子ａと端子ｄおよび
端子すと端子Ｃがそれぞれ接続される。また光送信器９
の動作を確認するだめの折り返し試験を行う場合には、
光スィッチ１０の端子ｄと端子Ｃが接続される。この従
来例においても第１図の従来例と同じように光スィッチ
１０の端子ｄでの反射光が光送信器９に戻るという欠点
がある。また、折り返し試験において光受信器８の受光
レベルが過大になるのを防ぐために、何らかの方法で光
送信器９から光受信器８へ至る光路において光パワーを
減衰する必要がある。FIG. 2 shows another conventional example. Except that the configuration of the optical switch at point A is different from that in Figure 1.
Same as Figure 1. In FIG. 2, when performing bidirectional optical communication, terminals a and d and terminals C and C of the optical switch 10 are connected, respectively. Also, the optical transmitter 9
When performing a loop test to confirm the operation of the
Terminal d and terminal C of optical switch 10 are connected. This conventional example also has the disadvantage that the reflected light at the terminal d of the optical switch 10 returns to the optical transmitter 9, as in the conventional example shown in FIG. Furthermore, in order to prevent the light reception level of the optical receiver 8 from becoming excessive in the foldback test, it is necessary to attenuate the optical power in the optical path from the optical transmitter 9 to the optical receiver 8 by some method.

発明の目的本発明は、上記従来例の欠点を除去するものであシ、折
り返し試験を行う光送信器への反射戻り光量を低く抑え
ること、および折り返し試験の際に、光減衰器等を用い
ることなく光受信器の光受光ハワーを適切な値まで小さ
くすること、光スィッチのような可動部品を減らすこと
、挿入損失を低減すること、小形化、低価格化を図るこ
とを目的とするものである。OBJECTS OF THE INVENTION The present invention eliminates the drawbacks of the conventional example described above, and aims to suppress the amount of light reflected back to the optical transmitter that performs the folding test, and to use an optical attenuator or the like during the folding test. The purpose is to reduce the optical reception power of the optical receiver to an appropriate value without causing damage, reduce moving parts such as optical switches, reduce insertion loss, and reduce size and cost. It is.

発明の構成本発明は、上記目的を達成するために、送信器出力光を
伝送路側と受信器側に分岐する部分に光分岐器を用い、
出力光の一部を常に受信器側に送るという構成で送信部
の折り返し試験を可能にしだものである。光分岐器はそ
の入射端子での反射を低減することが光スィッチに比べ
て非常に容易である。まだ、分岐比を適切に設定するこ
とによって、折り返し試験時の受信器の受光パワーを、
光減衰器等を用いることなく正常な受信が可能なレベル
まで減衰することができる。まだ、光分岐器は可動部品
ではないので、信頼性が向上する。Structure of the Invention In order to achieve the above object, the present invention uses an optical splitter in the part that branches the transmitter output light into the transmission line side and the receiver side,
This configuration enables loopback testing of the transmitter by always sending a portion of the output light to the receiver side. It is much easier to reduce reflection at the input terminal of an optical splitter than it is for an optical switch. However, by setting the branching ratio appropriately, the received power of the receiver during the loopback test can be adjusted to
The signal can be attenuated to a level that allows normal reception without using an optical attenuator or the like. Still, since the optical splitter is not a moving part, reliability is improved.

さらに光分岐器は光スィッチに比べて小形化、低価格化
、低挿入損失化が図れるという効果が得られる。Furthermore, the optical branching device has the advantage of being smaller, cheaper, and has lower insertion loss than an optical switch.

実施例の説明以下に本発明の一実施例の構成について、図面とともに
説明する。DESCRIPTION OF EMBODIMENTS The configuration of an embodiment of the present invention will be described below with reference to the drawings.

第３図において、９はＡ地点にある光送信器であり、こ
こから送信された光信号は光分岐器１１金介して光分波
合波器５を通シ光伝送路４へ送ら受信器１で受信される
。一方、２はＢ地点にある光送信器であり、ここから送
信された光信号は光分波合波器３により、光伝送路４へ
と送られる。In FIG. 3, reference numeral 9 is an optical transmitter located at point A, and the optical signal transmitted from this transmitter is passed through an optical branching multiplexer 5 via an optical branching device 11 and sent to an optical transmission line 4. 1 is received. On the other hand, 2 is an optical transmitter located at point B, and the optical signal transmitted from this transmitter is sent to an optical transmission line 4 by an optical demultiplexer/multiplexer 3.

そしてＡ地点に至り光分波合波器５で分波され、光スィ
ッチ１２の入力端子ｅへ送られる。通常の双方向光通信
状態においては、光スィッチ１２の端子ｅと端子ｄが接
続されており、Ｂ地点からＡ地点へと送られてきた光信
号は光受信器８で受信される。光送信器９の折り返し試
験を行う場合には、光スィッチ１２の端子ｆと端子ｄが
接続され、光分岐器１１の端子Ｃからの出力光が光受信
器８で受信される。The light then reaches point A, is demultiplexed by the optical demultiplexer/multiplexer 5, and is sent to the input terminal e of the optical switch 12. In a normal bidirectional optical communication state, terminals e and d of the optical switch 12 are connected, and an optical signal sent from point B to point A is received by the optical receiver 8. When performing a loopback test on the optical transmitter 9, the terminals f and d of the optical switch 12 are connected, and the output light from the terminal C of the optical splitter 11 is received by the optical receiver 8.

本実施例においては、光分岐器１１を用いているために
光送信器Ｉからの光が入力端子ａで反射して再び送信器
に戻る割合を低く抑えることが容易である。まだ、分岐
器の分岐比を適切に設定して、光分岐器の端子Ｃ側に分
岐する光パワーを光受信器８が受信可能なレベルまで小
さくすることを、光減衰器等を用いずに容易に行える。In this embodiment, since the optical branching device 11 is used, it is easy to suppress the proportion of light from the optical transmitter I that is reflected at the input terminal a and returns to the transmitter again. However, it is still possible to set the branching ratio of the splitter appropriately and reduce the optical power branched to the terminal C side of the optical splitter to a level that can be received by the optical receiver 8 without using an optical attenuator or the like. It's easy to do.

また、光分岐器は光スィッチと違い、可動部品ではない
ので信頼性にすぐれている。Furthermore, unlike optical switches, optical splitters do not have moving parts, so they are highly reliable.

第４図に光分岐器として用いることのできる埋込形光導
波路を示す。第４図において、１３は入力端子コネクタ
、１４および１５は出力端子コネクタ、１６，１７．１
８は光ファイバである。入力端子１３から入力した光は
導波路１９と２０の２方向へと分岐される。分岐器は導
波路の幅２分岐角度等により決定される。この埋込形光
導波路を光分岐器として用いれば、光スィッチに比較し
て非常に小形、安価、低挿入損失が実現できる。また、
入力端子コネクタ１３を斜めに研磨することによって、
送信器への反射戻シ光量も、実用上十分な値に抑えるこ
とが可能である。FIG. 4 shows a buried optical waveguide that can be used as an optical splitter. In Fig. 4, 13 is an input terminal connector, 14 and 15 are output terminal connectors, 16, 17.1
8 is an optical fiber. Light input from the input terminal 13 is branched into two directions of waveguides 19 and 20. The branching device is determined by the width of the waveguide, the two-branching angle, etc. If this embedded optical waveguide is used as an optical splitter, it can be much smaller, cheaper, and have lower insertion loss than an optical switch. Also,
By polishing the input terminal connector 13 diagonally,
The amount of light reflected back to the transmitter can also be suppressed to a practically sufficient value.

発明の効果本発明は上記のような構成であり、以下に示す効果が得
られるものである。Effects of the Invention The present invention has the above-described configuration, and provides the following effects.

（ａ）　送信器出力光を伝送路側と受信器側の２方向に
分けるのに、光スィッチではなく、光分岐器を用いてい
るために、送信器への反射戻り光量を小さな値に抑える
ことが容易である。(a) Since an optical splitter is used instead of an optical switch to divide the transmitter output light into two directions, the transmission line side and the receiver side, the amount of light reflected back to the transmitter can be kept to a small value. is easy.

（ｂ）　光スィッチではなく、光分岐器を用いているた
めに、分岐比を適当に設定することにより、折り返し試
験の場合に受信器が受光する光パワーを適切な値に抑え
ることができる。光スィッチの場合には、過大な光パワ
ーが受信器に人力するのを防ぐためには、光減衰器等を
用いる必要がある。(b) Since an optical splitter is used instead of an optical switch, by appropriately setting the branching ratio, the optical power received by the receiver can be suppressed to an appropriate value in the case of a loopback test. In the case of an optical switch, it is necessary to use an optical attenuator or the like to prevent excessive optical power from being applied to the receiver.

（Ｃ）　光分岐器は光スイッチ六人なり、可動部品では
ないので、信頼性にすぐれている。(C) The optical splitter consists of six optical switches and has no moving parts, so it has excellent reliability.

（ｄ）　光分岐器は光スィッチに比較して、小形で。(d) Optical splitters are smaller than optical switches.

安価で、低挿入損失である。光分岐器として埋込形溝波
路を用いれば、特にこの傾向は顕著である０It is inexpensive and has low insertion loss. This tendency is particularly noticeable when a buried groove waveguide is used as an optical splitter.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は従来の双方向光通信装置のブロック図、第２図
は他の従来例のブロック図、第３図は本発明の一実施例
における光通信装置のブロック図、第４図は第３図に示
す装置に用いる光分岐器の一例である埋込形光導波路の
概略図である。−１・・・光受信器、２・・・光送信器
、３・・・光分波合波器、４　・光伝送路、５・・・光
分波合波器、８・・・光受信器、９・光送信器、１１・
・・光分岐器、１２・・・光スィッチＯ代理人の氏名　弁理士　中　尾　敏　男　ほか１名第　
１　図第２図FIG. 1 is a block diagram of a conventional two-way optical communication device, FIG. 2 is a block diagram of another conventional example, FIG. 3 is a block diagram of an optical communication device according to an embodiment of the present invention, and FIG. 4 is a schematic diagram of a buried optical waveguide which is an example of an optical branching device used in the device shown in FIG. 3. FIG. -1... Optical receiver, 2... Optical transmitter, 3... Optical demultiplexer/multiplexer, 4 - Optical transmission line, 5... Optical demultiplexer/multiplexer, 8... Optical Receiver, 9・Optical transmitter, 11・
...Optical splitter, 12...Optical switch O Name of agent: Patent attorney Toshio Nakao and 1 other person
1 Figure 2

Claims

【特許請求の範囲】第１の光送信器、第１の光受信器、第１の光分波合波器
からなる第１の装置と、第２の光送信器。第２の光受信器、第２の光分波合波器からなる第２の装
置と、この第１．第２の装置を結ぶ光伝送路と、上記第
１の光送信器の出力光を、第１の光受信器側および上記
光伝送路側の２方向に分岐する光分岐器と、この光分岐
器で分岐された分岐光または第１の光分波合波器を介し
て第１の装置に入力された第２の装置の出力光を、第１
の光受信器に入力する光スィッチとからなる光通信装置
。Claims: A first device comprising a first optical transmitter, a first optical receiver, and a first optical demultiplexer/multiplexer, and a second optical transmitter. a second device consisting of a second optical receiver and a second optical demultiplexer/multiplexer; an optical transmission line that connects a second device; an optical splitter that branches the output light of the first optical transmitter into two directions, a first optical receiver side and an optical transmission line side; and the optical splitter. The output light of the second device input to the first device via the first optical demultiplexer/multiplexer is
An optical communication device consisting of an optical switch that inputs to an optical receiver.