JPH0310261B2 - - Google Patents
Info
- Publication number
- JPH0310261B2 JPH0310261B2 JP9414184A JP9414184A JPH0310261B2 JP H0310261 B2 JPH0310261 B2 JP H0310261B2 JP 9414184 A JP9414184 A JP 9414184A JP 9414184 A JP9414184 A JP 9414184A JP H0310261 B2 JPH0310261 B2 JP H0310261B2
- Authority
- JP
- Japan
- Prior art keywords
- optical
- signal
- wavelength
- output
- electrical
- 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.)
- Expired - Lifetime
Links
- 230000003287 optical effect Effects 0.000 claims description 116
- 230000005540 biological transmission Effects 0.000 description 32
- 238000012360 testing method Methods 0.000 description 18
- 230000002457 bidirectional effect Effects 0.000 description 11
- 239000013307 optical fiber Substances 0.000 description 7
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000004891 communication Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
- H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Testing Of Optical Devices Or Fibers (AREA)
- Monitoring And Testing Of Transmission In General (AREA)
- Optical Communication System (AREA)
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は光通信方式の試験回路に関する。特
に、双方向波長多重伝送方式で使用される試験用
光折り返し回路に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a test circuit for an optical communication system. In particular, the present invention relates to a test optical folding circuit used in a bidirectional wavelength division multiplexing transmission system.
〔従来の技術〕
光通信技術の中で重要なものの一つである波長
多重技術を利用した波長多重伝送方式が実用化さ
れつつあり、この方式の運用面での検討も重要で
ある波長多重伝送方式では、いくつかの異なる波
長の光信号を一本の光フアイバの中を通して伝送
するので、一本の光フアイバ当りの伝送容量を増
すあるいは双方向伝送を行うなどが可能であり、
伝送路コスト低減効果が期待されている。[Conventional technology] Wavelength division multiplexing transmission systems that utilize wavelength division multiplexing technology, which is one of the most important optical communication technologies, are being put into practical use, and it is also important to consider the operational aspects of this system. In this method, optical signals of several different wavelengths are transmitted through a single optical fiber, so it is possible to increase the transmission capacity per optical fiber or perform bidirectional transmission.
It is expected to reduce transmission line costs.
双方向波長多重伝送用装置の構成は大きくわけ
て、光送信部、光受信部および光合・分波部の３
つの部分からなる。この３つの部分を分割して実
装した場合の欠点としては光フアイバで各部分を
接続しなければならないことである。これでは光
フアイバが輻輳して取り扱いが煩雑となつてしま
う。それに実装上は、できるだけ光フアイバが外
へでない方が好ましい。 The configuration of a bidirectional wavelength multiplexing transmission device can be broadly divided into three parts: an optical transmitter, an optical receiver, and an optical multiplexer/demultiplexer.
It consists of two parts. A disadvantage of mounting these three parts separately is that each part must be connected with an optical fiber. In this case, the optical fibers become congested and handling becomes complicated. In addition, from a mounting standpoint, it is preferable that the optical fibers do not extend outside as much as possible.
そこで、光送信部、光受信部、光合・分波部の
３つを一体化して１つのパツケージに収めること
によつて、外へ出る光フアイバは伝送路側の１体
だけとなり、前述したような実装上の問題は少な
くなる。 Therefore, by integrating the optical transmitting section, optical receiving section, and optical multiplexing/demultiplexing section into one package, the only optical fiber that goes out is the one on the transmission line side. There are fewer implementation problems.
このようにして、一つのパツケージに光送信
部、光受信部、および光合・分波部を一体化する
と、その性能を確認するために、伝送路へ出力す
る信号を自局へ戻して信号の導通を見る「折り返
し試験」が難しくなつてしまつた。 In this way, when the optical transmitting section, optical receiving section, and optical multiplexing/demultiplexing section are integrated into one package, in order to check its performance, the signal output to the transmission path is returned to the local station. The ``return test'' to check continuity has become difficult.
光送信部、光受信部と光合・分波部の３つに分
割されていれば折り返し試験を行う場合には、光
送信部から光部・分波部を通さずに直接光受信部
へ光信号を戻して、信号を通すことが可能である
が、一体化されている場合は、伝送装置の伝送路
側の出力が１つしかないため、光送信部から出力
された信号は、光合・分波部を通り一旦伝送路側
へ出た後また、光合・分波部へ戻され、光受信部
へ入力される。この双方向波長多重伝送方式で
は、送信側の波長と受信側の波長が異なり、光
合・分波部でそれらを波長によつて合波および分
波しているので、原理的に自局の送信側の信号
は、光合・分波部を通して受信側へ戻すことは不
可能である。これを可能にするためには、光送信
部からの光信号波長と異なる波長（例えば光受信
部へ入る波長と同じ波長）の信号に変換して戻す
必要がある。 If the optical transmitter is divided into three parts: an optical transmitter, an optical receiver, and an optical multiplexer/demultiplexer, when performing a loop test, the light is sent directly from the optical transmitter to the optical receiver without passing through the optical receiver/multiplexer. It is possible to return the signal and pass the signal, but if it is integrated, there is only one output on the transmission line side of the transmission device, so the signal output from the optical transmitter is optically combined and separated. After passing through the wave section and once exiting to the transmission line side, it is returned to the optical multiplexing/demultiplexing section and input to the optical receiving section. In this bidirectional wavelength division multiplexing transmission system, the wavelengths on the transmitting side and the wavelengths on the receiving side are different, and the optical multiplexing/demultiplexing section combines and demultiplexes them depending on the wavelength. It is impossible to return the signal from the receiving side to the receiving side through the optical multiplexing/demultiplexing section. In order to make this possible, it is necessary to convert the optical signal from the optical transmitter into a signal with a different wavelength (for example, the same wavelength as the wavelength entering the optical receiver) and return it.
本発明は、異なる波長２波による双方向波長多
重伝送装置の試験において、出力された光信号を
波長の異なる信号に変換して、伝送装置の自局折
り返し試験を行うことができるような試験用光信
号折り返し回路を提供することを目的とする。
The present invention is a test device that converts an output optical signal into a signal with a different wavelength in testing a bidirectional wavelength division multiplexing transmission device using two waves of different wavelengths, and performs a self-return test of the transmission device. The purpose is to provide an optical signal folding circuit.
本発明は、光信号が入力する入出力端子と、こ
の入出力端子に共通端子が接続された方向性結合
器と、この方向性結合器の出力端子に入力が接続
され入力光信号をその波長と異なる出力光信号に
変換して出力する多波長式片方向光中継器と、こ
の多波長式片方向光中継器の出力を通過しその出
力を前記方向性結合器の入力端子に接続する光導
波路とを備え、前記多波長式片方向光中継器は、
入力光信号を波長毎に分波する光分波器と、この
光分波器の各出力波長をそれぞれ電気信号に変換
する複数の光−電気変換器と、この複数の光−電
気変換器の出力電気信号をそれぞれ前記各出力波
長と異なる波長の複数の光信号に変換する電気−
光変換器と、この複数の光信号を合波する光合波
器と、前記複数の光−電気変換器の出力レベルを
比較してその最大レベルの光−電気変換器以外の
出力信号通路を遮断する手段とを含むことを特徴
とする。
The present invention includes an input/output terminal into which an optical signal is input, a directional coupler having a common terminal connected to the input/output terminal, and an input connected to the output terminal of the directional coupler to transmit the input optical signal at its wavelength. a multi-wavelength unidirectional optical repeater that converts the signal into a different output optical signal and outputs the same; and an optical guide that passes through the output of the multi-wavelength unidirectional optical repeater and connects the output to the input terminal of the directional coupler. The multi-wavelength unidirectional optical repeater comprises:
An optical demultiplexer that demultiplexes an input optical signal into wavelengths, a plurality of optical-to-electrical converters that convert each output wavelength of the optical demultiplexer into an electrical signal, and a plurality of optical-to-electrical converters. an electrical converter for converting the output electrical signal into a plurality of optical signals each having a wavelength different from each of the output wavelengths;
Compares the output levels of an optical converter, an optical multiplexer that combines the plurality of optical signals, and the plurality of optical-to-electrical converters, and blocks output signal paths other than the optical-to-electrical converter with the maximum level. It is characterized by including means for.
次に本発明による試験用光信号折り返し回路を
用いて、双方向波長多重用伝送装置の試験を行う
場合には、伝送装置から波長λ1で出力された光信
号は、本発明の試験用光信号折り返し回路で波長
λ2の光信号に交換された後、光可変減衰器でレベ
ル調整され、上記伝送装置側に戻される。この戻
された信号は光合・分波器で分波され、光−電気
変換器へ入力されてもとの電気信号へ交換され
る。すなわち伝送装置の電気信号入力端子から電
気信号出力端子へ信号が戻されて伝送路の折り返
し試験が行われる。
Next, when testing a bidirectional wavelength multiplexing transmission device using the test optical signal folding circuit according to the present invention, the optical signal output from the transmission device at wavelength λ 1 is the test optical signal according to the present invention. After being exchanged into an optical signal of wavelength λ 2 in a signal folding circuit, the level is adjusted by a variable optical attenuator, and the signal is returned to the transmission device. This returned signal is demultiplexed by an optical multiplexer/demultiplexer, inputted to an optical-to-electrical converter, and exchanged into the original electrical signal. That is, a signal is returned from the electrical signal input terminal of the transmission device to the electrical signal output terminal, and a loopback test of the transmission path is performed.
次に図面を用いて、本発明の実施例について説
明する。
Next, embodiments of the present invention will be described using the drawings.
第１図は、本発明実施例装置を示すブロツク構
成図である。図面符号１は本試験用光信号折り返
し回路の入・出力端子、２は光の方向性結合器、
３は２波長式片方向中継器、４は電圧比較器、５
は光の可変減衰器を示す。光の方向性結合器２の
出力は、２波長式片方向光中継器３を介して光の
可変減衰器５に入力する。この可変減衰器５の出
力は、光の方向性結合器２の他方の入力に接続さ
れる。上記２波長式片方向中継器３の光分波器３
１の光合波器３２との間に、光−電気変換器３２
と電気−光変換器３５の縦続接続回路と、光−電
気変換器３４と電気−光変換器３６の縦続接続回
路との並列回路が介在する。光−電気変換器３３
と３４は電圧比較器４の入力に結合し、電気−光
変換器３５と３６は電気比較器４の出力側に結合
する。 FIG. 1 is a block diagram showing an apparatus according to an embodiment of the present invention. Drawing code 1 is the input/output terminal of the optical signal folding circuit for this test, 2 is the optical directional coupler,
3 is a two-wavelength unidirectional repeater, 4 is a voltage comparator, 5
indicates a variable optical attenuator. The output of the optical directional coupler 2 is input to the optical variable attenuator 5 via the two-wavelength unidirectional optical repeater 3. The output of the variable attenuator 5 is connected to the other input of the optical directional coupler 2. Optical demultiplexer 3 of the two-wavelength unidirectional repeater 3
An optical-to-electrical converter 32 is connected between the optical multiplexer 32 of
A parallel circuit consisting of a cascade connection circuit of the optical-electrical converter 34 and the electric-optical converter 36 is interposed. Light-electric converter 33
and 34 are coupled to the inputs of the voltage comparator 4, and electro-optical converters 35 and 36 are coupled to the outputs of the electrical comparator 4.
本発明は、波長多重伝送用光中継器用であるた
め電気−光変換器３５と３６との光出力信号の波
長は異なる。入・出力端子１へ入力された光信号
は、方向性結合器２を通つて２波長式片方向光中
継器３へ入力される。この光中継器３へ入力され
た光信号は、光分波器３１でその波長によつて光
−電気変換器３３あるいは３４へ入力され各々電
気信号に変換され、再び電気−光変換器３４およ
び３６で光信号へ変換され、光合波器３２で合波
され、光可変減衰器５を通り、方向性結合器２で
入・出力端子１からもとの方向へ戻される。一方
光−電気変換器３３，３４で光信号が電気信号に
変換されるとともにその光信号のレベルに応じた
電圧を電圧比較器４で、比較し、光レベルの低い
方の電気−光変換器の光出力を「断」とする。こ
れは、２波長式片方向光中継器３の入力信号の波
長とその出力信号の波長とが異なり、また、その
出力信号が光の方向性結合器２で一部廻り込んで
光中継器３へ漏れ込むために、光中継器３の出力
からは、２つの波長の光信号が出力されてしまう
ことを防ぐためである。 Since the present invention is for an optical repeater for wavelength division multiplex transmission, the wavelengths of the optical output signals of the electro-optical converters 35 and 36 are different. The optical signal input to the input/output terminal 1 passes through the directional coupler 2 and is input to the two-wavelength unidirectional optical repeater 3. The optical signal input to the optical repeater 3 is input to the optical demultiplexer 31 and the optical-to-electrical converter 33 or 34 depending on its wavelength, where it is converted into an electric signal, and then again to the electric-to-optical converter 34 or 34. The signal is converted into an optical signal at 36, multiplexed at an optical multiplexer 32, passed through an optical variable attenuator 5, and returned to the original direction from the input/output terminal 1 at a directional coupler 2. On the other hand, the optical signals are converted into electrical signals by the optical-to-electrical converters 33 and 34, and the voltages corresponding to the levels of the optical signals are compared by the voltage comparator 4, and the electrical-to-optical converter with the lower optical level is The light output is set to "off". This is because the wavelength of the input signal of the two-wavelength type unidirectional optical repeater 3 is different from the wavelength of its output signal, and the output signal is partially routed through the optical directional coupler 2 to the optical repeater 3. This is to prevent optical signals of two wavelengths from being output from the output of the optical repeater 3 due to leakage into the optical fiber.
一般的には伝送装置などの「折り返し試験」で
は、受信レベルの低い所で動作するかどうかをチ
エツクするために、伝送装置の光出力レベルより
もずつと低いレベルの光信号を折り返すことにな
る。すなわち、その光信号折り返し回路Ａで用い
ている光中継器３の入力では、光中継器出力の
「もれ込み信号」よりも伝送装置から光信号のレ
ベルの方が大きく、この大きいレベルの方の光中
継器出力だけを電圧比較器４で選択することにな
る。 Generally, in "foldback testing" of transmission equipment, etc., an optical signal with a level lower than the optical output level of the transmission equipment is looped back in order to check whether it will work in an area where the reception level is low. . That is, at the input of the optical repeater 3 used in the optical signal return circuit A, the level of the optical signal from the transmission device is higher than the "leakage signal" of the optical repeater output, and this higher level Only the output of the optical repeater is selected by the voltage comparator 4.
次に第２図は、本発明による第１図試験用光信
号折り返し回路Ａを用いて、双方向波長多重用伝
送装置６の試験を行うブロツク構成回路図を示
す。この伝送装置６からλ1の波長で出力された光
信号は、光信号折り返し回路Ａでλ2の波長の光信
号に変換された後に光可変減衰器５でレベル調整
され伝送装置に戻される。戻された信号は光合・
分波器６１で分波され、光−電気変換器６３へ入
力されて、もとの電気信号へ変換される。すなわ
ち伝送装置６の電気信号入力端子７から電気信号
出力端子８へ信号が戻されて、折り返し試験が可
能となる。 Next, FIG. 2 shows a block configuration circuit diagram for testing the bidirectional wavelength multiplexing transmission device 6 using the test optical signal folding circuit A of FIG. 1 according to the present invention. The optical signal outputted from the transmission device 6 with a wavelength of λ 1 is converted into an optical signal with a wavelength of λ 2 by an optical signal folding circuit A, and then level-adjusted by an optical variable attenuator 5 and returned to the transmission device. The returned signal is
The signal is demultiplexed by a demultiplexer 61, inputted to an optical-to-electrical converter 63, and converted into the original electrical signal. That is, the signal is returned from the electrical signal input terminal 7 of the transmission device 6 to the electrical signal output terminal 8, making it possible to perform a return test.
本発明は２波長のものについては説明したが２
波長ものに限定されるものでなく、波長多重もの
についても拡張することが可能である。 Although the present invention has been described with reference to two wavelengths,
The present invention is not limited to wavelengths, but can also be extended to wavelength multiplexing.
以上説明したように、本発明によれば、任意の
波長の光信号に対して自動的にそれと異なる波長
の光信号に変換して戻す、光波長変換回路を構成
して、容易に双方向波長多重用光伝送装置の光信
号折り返し試験が可能となる効果がある。
As explained above, according to the present invention, an optical wavelength conversion circuit that automatically converts an optical signal of an arbitrary wavelength into an optical signal of a different wavelength and returns it can be configured to easily perform bidirectional wavelength conversion. This has the effect of enabling optical signal return testing of multiplex optical transmission equipment.
第１図は本発明の実施例装置に示すブロツク構
成図。第２図は本発明による第１図実施例回路を
用いて、伝送装置の折り返し試験を行うブロツク
構成回路図。
１……光信号折り返し回路の入出力端子、２…
…光の方向性結合器、３……２波長式片方向光中
継器、４……電圧比較器、５……光の可変減衰
器、６……双方向波長多重用光伝送装置、７……
双方向用光伝送装置の電気信号入力端子、８……
双方向用光伝送装置の電気信号出力端子、３１…
…光分波器、３２……光合波器、３３，３４，６
３……光−電気変換器、３５，３６，６２……電
気−光変換器、６１……光合分波器、Ａ……光信
号折り返し回路。
FIG. 1 is a block diagram showing an embodiment of the present invention. FIG. 2 is a block configuration circuit diagram for carrying out a loopback test of a transmission device using the circuit according to the embodiment of FIG. 1 according to the present invention. 1... Input/output terminal of optical signal folding circuit, 2...
... Optical directional coupler, 3... Two-wavelength unidirectional optical repeater, 4... Voltage comparator, 5... Optical variable attenuator, 6... Bidirectional wavelength multiplexing optical transmission device, 7... …
Electrical signal input terminal of bidirectional optical transmission device, 8...
Electrical signal output terminal of bidirectional optical transmission device, 31...
...Optical demultiplexer, 32... Optical multiplexer, 33, 34, 6
3... Optical-electrical converter, 35, 36, 62... Electrical-optical converter, 61... Optical multiplexer/demultiplexer, A... Optical signal return circuit.
Claims (1)
結合器と、 この方向性結合器の出力端子に入力が接続され
入力光信号をその波長と異なる出力光信号に変換
して出力する多波長式片方向光中継器と、 この多波長式片方向光中継器の出力を通過しそ
の出力を前記方向性結合器の入力端子に接続する
光導波路と を備え、 前記多波長式片方向光中継器は、入力光信号を
波長毎に分波する光分波器と、この光分波器の各
出力波長をそれぞれ電気信号に変換する複数の光
−電気変換器と、この複数の光−電気変換器の出
力電気信号をそれぞれ前記各出力波長と異なる波
長の複数の光信号に変換する電気−光変換器と、
この複数の光信号を合波する光合波器と、前記複
数の光−電気変換器の出力レベルを比較してその
最大レベルの光−電気変換器以外の出力信号通路
を遮断する手段とを含む 光信号折り返し回路。[Claims] 1: an input/output terminal into which an optical signal is input; a directional coupler with a common terminal connected to the input/output terminal; a multi-wavelength unidirectional optical repeater that converts the signal into an output optical signal different from that wavelength and outputs the same; The multi-wavelength unidirectional optical repeater includes an optical demultiplexer that demultiplexes an input optical signal into each wavelength, and converts each output wavelength of the optical demultiplexer into an electrical signal. a plurality of optical-to-electrical converters that convert the output electrical signals of the plurality of optical-to-electrical converters into a plurality of optical signals having wavelengths different from each of the output wavelengths;
It includes an optical multiplexer that multiplexes the plurality of optical signals, and a means for comparing the output levels of the plurality of optical-to-electrical converters and cutting off the output signal paths other than the optical-to-electrical converter having the maximum level. Optical signal folding circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59094141A JPS60237736A (en) | 1984-05-11 | 1984-05-11 | Returning circuit for light signal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59094141A JPS60237736A (en) | 1984-05-11 | 1984-05-11 | Returning circuit for light signal |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60237736A JPS60237736A (en) | 1985-11-26 |
| JPH0310261B2 true JPH0310261B2 (en) | 1991-02-13 |
Family
ID=14102102
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59094141A Granted JPS60237736A (en) | 1984-05-11 | 1984-05-11 | Returning circuit for light signal |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60237736A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4879763A (en) * | 1986-02-21 | 1989-11-07 | AT&T Bell Laboratories American Telephone and Telegraph Company | Optical fiber bidirectional transmission system |
| JP2512770B2 (en) * | 1987-10-27 | 1996-07-03 | 富士通株式会社 | WDM optical communication device |
| GB2425904A (en) * | 2005-05-03 | 2006-11-08 | Marconi Comm Gmbh | Optical network fault test apparatus which modifies a received test signal using a passive optical device to generate a response signal |
-
1984
- 1984-05-11 JP JP59094141A patent/JPS60237736A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60237736A (en) | 1985-11-26 |
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