JPS6322694B2 - - Google Patents
Info
- Publication number
- JPS6322694B2 JPS6322694B2 JP56171925A JP17192581A JPS6322694B2 JP S6322694 B2 JPS6322694 B2 JP S6322694B2 JP 56171925 A JP56171925 A JP 56171925A JP 17192581 A JP17192581 A JP 17192581A JP S6322694 B2 JPS6322694 B2 JP S6322694B2
- Authority
- JP
- Japan
- Prior art keywords
- optical fiber
- light
- fiber line
- frequency
- monitoring
- 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
Links
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
-
- 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
- H04B10/071—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
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)
- Optical Communication System (AREA)
Description
【発明の詳細な説明】
本発明は光フアイバ線路を用いた通信方式で、
その光フアイバ線路の状態を監視するための方式
に関する。特に、簡易な構成で高い信頼性のある
監視方式に関する。[Detailed Description of the Invention] The present invention is a communication system using optical fiber lines,
The present invention relates to a method for monitoring the state of the optical fiber line. In particular, it relates to a monitoring method that has a simple configuration and high reliability.
通信用の光フアイバ線路の試験または監視を行
うために、その光フアイバの一端から光を入射さ
せ、他端でその光を反射させ、この反射させた光
を上記一端で検出する技術が知られている。これ
は、上記他端には一定の反射の状態を設定してお
きさえすれば、特にこの他端で試験または監視に
合わせて操作を行う必要のない便利な方法である
が、上記一端に到来する反射光が確実に上記他端
で反射した光であることを区別することがむつか
しい。入射光をパルス状にすれば、ある程度距離
の違う部分での反射を区別することはできるが、
上記他端に主通信情報を送受信するための装置が
接続されている場合には、その反射光がどの部分
で生じた反射光であるのかの区別ができない。 In order to test or monitor optical fiber lines for communication, there is a known technology in which light is incident on one end of the optical fiber, the light is reflected at the other end, and the reflected light is detected at the one end. ing. This is a convenient method that does not require any special operation at the other end for testing or monitoring, as long as a certain state of reflection is set at the other end. It is difficult to distinguish with certainty that the reflected light reflected at the other end is the light reflected at the other end. If the incident light is pulsed, it is possible to distinguish reflections at different distances to some extent, but
If a device for transmitting and receiving main communication information is connected to the other end, it is not possible to distinguish from which part the reflected light originates.
また、主通信情報が伝送されている状態では、
その主通信情報に妨害を与えないようにパルスを
入射しまた反射させることはむつかしい。 Also, while the main communication information is being transmitted,
It is difficult to inject and reflect pulses without interfering with the main communication information.
本発明はこれを改良するもので、上記のように
他端で反射の状態を設定すれば、試験または監視
を一端からのみで行うことができる利点を失うこ
となく、他端における反射光を確実に区別して試
験または監視を行うことができる方式を提供する
ことを目的とする。 The present invention improves on this by setting the reflection state at the other end as described above, ensuring that the reflected light at the other end is reflected without losing the advantage of being able to test or monitor only from one end. The purpose is to provide a method that allows testing or monitoring to be performed separately.
本発明は、被監視光フアイバ線路の一端から光
を入射させ、この光フアイバの他端では、その反
射率が特定の周波数で変化するようにしてこの光
を反射させ、さらに上記一端ではこの反射光から
上記特定の周波数で変調された成分を検出するこ
とを特徴とする。 The present invention allows light to enter from one end of an optical fiber line to be monitored, and reflects this light at the other end of the optical fiber such that its reflectance changes at a specific frequency, and furthermore, at the one end, this light is reflected. It is characterized by detecting a component modulated at the above-mentioned specific frequency from light.
実施例図面を参照してさらに詳しく説明する。 This will be explained in more detail with reference to the drawings.
第１図は本発明の実施例装置の構成図である。
１は入射光、２は光方向性結合器、３は被監視光
フアイバ線路である。４は特定の周波数で反射率
を変化させることのできる反射装置である。５は
反射装置４に特定の周波数を供給する発振器であ
る。６は光フアイバ線路３からの反射光、７は反
射光６を電気信号に変換する光電気変換装置、８
は変換された電気信号を表わす。 FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention.
1 is an incident light, 2 is an optical directional coupler, and 3 is an optical fiber line to be monitored. 4 is a reflection device that can change reflectance at a specific frequency. 5 is an oscillator that supplies a specific frequency to the reflection device 4. 6 is the reflected light from the optical fiber line 3; 7 is a photoelectric conversion device that converts the reflected light 6 into an electrical signal; 8
represents the converted electrical signal.
第１図において、入射光１は光方向性結合器２
を通つて、光フアイバ線路３に入射され、光フア
イバ線路３の他端に設置された反射装置４に達す
る。反射装置４は発振器５から供給される特定の
周波数f1でその反射装置４の反射率を変化させ
る。光フアイバ線路３を伝搬してきた光は発振器
５の周波数f1で変調されて入射端に戻り、再び光
方向性結合器２を通つて、光電気変換装置７で電
気信号８に変換される。 In FIG. 1, incident light 1 is transmitted to an optical directional coupler 2.
The light is incident on the optical fiber line 3 through the optical fiber line 3, and reaches a reflection device 4 installed at the other end of the optical fiber line 3. The reflector 4 changes its reflectance at a particular frequency f 1 supplied by the oscillator 5 . The light propagating through the optical fiber line 3 is modulated at the frequency f 1 of the oscillator 5 and returns to the input end, passes through the optical directional coupler 2 again, and is converted into an electrical signal 8 by the opto-electrical converter 7 .
ここで電気信号８から特定の周波数f1の成分を
検出すれば、光フアイバ線路３が断線しているか
否か、さらにその特性状態を遠端で確認すること
ができる。この方式によれば、入射光１が光方向
性結合器２や光フアイバ線路３の途中で反射され
ても、その反射光は周波数f1の周波数成分を持た
ないため、光フアイバ線路端に設置されている反
射装置４からの反射光と区別することができる。 Here, if a component of a specific frequency f 1 is detected from the electric signal 8, it is possible to check whether the optical fiber line 3 is disconnected or not, and further check its characteristic state at the far end. According to this method, even if the incident light 1 is reflected in the middle of the optical directional coupler 2 or the optical fiber line 3, the reflected light does not have a frequency component of frequency f1 , so it is installed at the end of the optical fiber line. It can be distinguished from the reflected light from the reflecting device 4, which is
ここで、反射装置４は、その一例として液晶で
ある。液晶の反射特定は電界により制御すること
ができるので、発振器５から与えられる周波数f1
の電気信号でこの電界を形成することができる。 Here, the reflection device 4 is, for example, a liquid crystal. Since the reflection characteristics of the liquid crystal can be controlled by an electric field, the frequency f 1 given from the oscillator 5
This electric field can be created by an electric signal of
反射装置４の素子としては、液晶の他の電気光
学効果を利用した各種の素子、音響光学効果を利
用した各種の素子、磁気光学効果を利用した各種
の素子を用いることができる。 As the elements of the reflection device 4, various types of elements using electro-optic effects other than liquid crystal, various types of elements using acousto-optic effects, and various types of elements using magneto-optic effects can be used.
次に第二の実施例について説明すると、この例
は同じく第１図で入射光１をあらかじめ前記周波
数f1より高い周波数f0により変調しておくことに
特徴がある。すなわち、第２図Ａに示すように、
あらかじめ周波数f0で変調された入射光１を光フ
アイバ線路３に入射し、反射装置４で反射させ
る。これによりその反射光は第２図Ｂに示すよう
に周波数f0に周波数f1が重畳変調されたものとな
る。 Next, a second embodiment will be described. This example is also shown in FIG. 1 and is characterized in that the incident light 1 is modulated in advance with a frequency f 0 higher than the frequency f 1 . That is, as shown in FIG. 2A,
Incident light 1 modulated in advance at a frequency f 0 enters an optical fiber line 3 and is reflected by a reflection device 4 . As a result, the reflected light becomes one in which the frequency f 1 is superimposed and modulated on the frequency f 0 as shown in FIG. 2B.
受信側では、この反射光を受信し光電気変換装
置７でこれを電気信号に変換する。この変換によ
り得られた電気信号２を包絡線検波すると、周波
数f1の成分をもつ第２図Ｃに示すような信号が抽
出される。 On the receiving side, this reflected light is received and converted into an electrical signal by a photoelectric conversion device 7. When the electrical signal 2 obtained by this conversion is subjected to envelope detection, a signal as shown in FIG. 2C having a frequency f 1 component is extracted.
このように構成することにより、低い周波数f1
により発生する歪の影響を避けることができる。
すなわち、反射装置４では反射素子を応動させる
ために周波数f1をかなり低い値に選ばなければな
らない。この場合に受光回路の低域遮断特性や電
気光変換回路の熱特性のために、周波数f1は歪を
受け易くなる。この歪は不要波を発生する。上述
のように重畳変調することにより、受信回路をス
ーパーヘテロダイン方式とすることができるの
で、この不要波の除去が容易になる。 By configuring in this way, the low frequency f 1
The influence of distortion caused by this can be avoided.
That is, in the reflection device 4 the frequency f 1 must be chosen to be fairly low in order to cause the reflection elements to respond. In this case, the frequency f 1 becomes susceptible to distortion due to the low frequency cut-off characteristics of the light receiving circuit and the thermal characteristics of the electro-optical conversion circuit. This distortion generates unnecessary waves. By superimposing modulation as described above, the receiving circuit can be of a superheterodyne type, so that it becomes easy to remove these unnecessary waves.
この場合にも同様に光フアイバ線路３の途中な
ど反射装置４以外での反射点からの反射光から
は、周波数f1の成分が検出されないので、これを
区別することができ、光フアイバ線路の特性を正
しく知ることができる。 In this case as well, since the frequency f 1 component is not detected from the reflected light from the reflection point other than the reflection device 4, such as in the middle of the optical fiber line 3, it is possible to distinguish this component. You can know the characteristics correctly.
次に第三の実施例として、光フアイバ線路が二
分岐されている場合を第３図に示す。第３図にお
いて、光フアイバ線路３は途中で二分岐されてい
るが、その分岐された他端の各々に反射装置４，
４′を接続し、反射装置４は周波数f1で、反射装
置４′はf1とは異なる周波数f2で駆動する。入力
端では反射光からは変調周波数成分f1，f2を抽出
すれば、それぞれの反射装置４，４′からの反射
を区別して受信することができる。これにより個
別に分岐された光フアイバ線路を監視することが
できる。 Next, as a third embodiment, a case where the optical fiber line is branched into two is shown in FIG. In FIG. 3, the optical fiber line 3 is branched into two in the middle, and a reflection device 4 is attached to each of the other ends of the branch.
4' is connected, the reflector 4 is driven at a frequency f 1 and the reflector 4' is driven at a frequency f 2 different from f 1 . At the input end, by extracting the modulated frequency components f 1 and f 2 from the reflected light, it is possible to distinguish and receive the reflections from the respective reflection devices 4 and 4'. This makes it possible to monitor individually branched optical fiber lines.
これは二分岐の例であるが、光フアイバ線路が
三分岐以上されていても、それぞれの発振器に異
なる周波数を割当てれば同様に実施することがで
きる。 Although this is an example of two branches, the same implementation is possible even if the optical fiber line is branched into three or more, by assigning different frequencies to each oscillator.
第４図に第四の実施例の部分構成図を示す。こ
の例は光フアイバ線路中に伝送されている情報通
信用信号に影響を与えないように、情報通信用の
光信号の波長とは異なる波長の監視用の光信号を
使用するものである。第４図において９は情報通
信用の光１０と監視用の光１１を分波および合波
する装置を表わす。この装置９には周波数選択性
の素子が用いられる。情報通信用の光１０は光フ
アイバ線路３を通つて分波合波装置９で監視用の
光１１と分離され通信に使用される。 FIG. 4 shows a partial configuration diagram of the fourth embodiment. In this example, a monitoring optical signal having a wavelength different from that of the information communication optical signal is used so as not to affect the information communication signal transmitted in the optical fiber line. In FIG. 4, numeral 9 represents a device for demultiplexing and multiplexing light 10 for information communication and light 11 for monitoring. This device 9 uses a frequency selective element. Light 10 for information communication passes through optical fiber line 3, is separated from light 11 for monitoring by demultiplexing/multiplexing device 9, and is used for communication.
監視用の光１１は光フアイバ線路３を通つて、
分波合波装置９で分離された後に、反射装置４で
反射され、再び分波合波装置９から光フアイバ線
路３を通つて、入射端に戻される。 The monitoring light 11 passes through the optical fiber line 3,
After being separated by the demultiplexing/multiplexing device 9, it is reflected by the reflection device 4, and returned from the demultiplexing/multiplexing device 9 through the optical fiber line 3 to the input end.
このような構成では、監視を行うときに、入射
端では情報通信用の光源をはずして監視用の光源
の光のみを入射してもよく、または情報通信用光
源の光と監視用の光とを同時に入射してもよい。
入射端では反射装置４からの反射光を光電気変換
し、周波数f1の成分を検出することによつて光フ
アイバ線路３の監視を行う。 In such a configuration, when performing monitoring, the light source for information communication may be removed at the input end and only the light from the light source for monitoring may be incident, or the light from the light source for information communication and the light for monitoring may be combined. may be injected at the same time.
At the input end, the optical fiber line 3 is monitored by photoelectrically converting the reflected light from the reflection device 4 and detecting the frequency f 1 component.
次に第五の実施例装置の部分構成図を第５図に
示す。この例も、監視用の装置が主通信情報信号
に影響を与えないように構成したものである。第
５図において、１４は通過と反射の二つのモード
をもつ反射装置である。１５は接続用光フアイ
バ、１６は情報通信用受信装置を表わす。この反
射装置１４は、二つのモードが切替えて設定でき
るように構成され、第一のモードでは光フアイバ
線路３の光を反射し、そのときの反射率は発振器
５の出力周波数f1で変化する。また第二のモード
では光フアイバ線路３を接続用光フアイバ１５と
直結する。 Next, FIG. 5 shows a partial configuration diagram of the apparatus of the fifth embodiment. This example is also configured so that the monitoring device does not affect the main communication information signal. In FIG. 5, 14 is a reflection device having two modes: transmission and reflection. Reference numeral 15 represents a connecting optical fiber, and 16 represents an information communication receiving device. This reflection device 14 is configured to be able to switch between two modes; in the first mode, it reflects the light from the optical fiber line 3, and the reflectance at that time changes with the output frequency f 1 of the oscillator 5. . In the second mode, the optical fiber line 3 is directly connected to the connecting optical fiber 15.
このように、通過と反射の二つのモードをもつ
反射装置１４を使用し、主通信情報の通信中には
光を通過させ、監視中には光を反射させれば、主
情報通信を行うときでも反射装置１４を取り除く
必要はない。 In this way, by using the reflecting device 14 which has two modes of transmission and reflection, and allowing light to pass during communication of the main communication information and reflecting the light during monitoring, it is possible to transmit the main communication information. However, it is not necessary to remove the reflector 14.
第５図で装置１６は無反射終端装置とすること
ができる。 In FIG. 5, device 16 may be a non-reflective termination device.
本発明の方式ではパルス性の信号を用いる必要
がないので、信号の帯域幅を小さく制限すること
ができるから、主通信情報の光と監視用の光とは
その相互干渉を小さくすることができる。 Since the method of the present invention does not require the use of pulsed signals, the signal bandwidth can be limited to a small value, so mutual interference between the main communication information light and the monitoring light can be reduced. .
以上説明したように、本発明の方式を光フアイ
バ線路の監視に用いれば、光フアイバ線路端から
の反射光をその他の不要な反射光と正確に区別す
ることができ、信頼度の高い監視を行うことがで
きる。また、本発明を実施するための装置構成は
きわめて簡単であつて、経済的に実施することが
できる。さらに、監視用の光の波長を主通信情報
を伝搬する光の波長と異なるようにすれば、その
相互干渉をきわめて小さくすることができる。 As explained above, if the method of the present invention is used to monitor optical fiber lines, the reflected light from the end of the optical fiber line can be accurately distinguished from other unnecessary reflected light, allowing highly reliable monitoring. It can be carried out. Furthermore, the device configuration for implementing the present invention is extremely simple and can be implemented economically. Furthermore, by making the wavelength of the monitoring light different from the wavelength of the light that propagates the main communication information, mutual interference can be extremely reduced.
第１図は本発明の第一実施例装置の構成図。第
２図は本発明の第二実施例の波形を示す図。第３
図は本発明の第三実施例装置の構成図。第４図は
本発明の第四実施例装置の要部構成図。第５図は
本発明の第五実施例装置の要部構成図。
１…入射光、２…光方向性結合器、３…被監視
光フアイバ線路、４，４′，１４…反射装置、５，
５′…発振器、６…反射光、７…光電気変換装置、
８…電気信号、９…分波合波装置、１０…情報通
信用の光、１１…監視用の光、１５…接続用光フ
アイバ、１６…情報通信用受信装置。
FIG. 1 is a configuration diagram of a device according to a first embodiment of the present invention. FIG. 2 is a diagram showing waveforms of a second embodiment of the present invention. Third
The figure is a configuration diagram of a device according to a third embodiment of the present invention. FIG. 4 is a diagram illustrating the configuration of main parts of a device according to a fourth embodiment of the present invention. FIG. 5 is a block diagram of the main parts of a device according to a fifth embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Incident light, 2... Optical directional coupler, 3... Optical fiber line to be monitored, 4, 4', 14... Reflector, 5,
5'... Oscillator, 6... Reflected light, 7... Photoelectric conversion device,
8... Electric signal, 9... Demultiplexing/multiplexing device, 10... Light for information communication, 11... Light for monitoring, 15... Optical fiber for connection, 16... Receiving device for information communication.
Claims (1)
バ線路内に光を入射する入射手段を備え、この光
フアイバ線路の他端にその光を反射させその反射
率が特定の周波数で変化するように構成された反
射手段を備え、上記一端に上記他端方向から到来
する光から上記特定の周波数で変調された成分を
検出する検出手段を備えた光フアイバ線路の監視
方式。 ２ 光フアイバ線路が２以上に分岐された光フア
イバ線路であり、分岐された各他端に反射手段を
備え、この各他端の特定の周波数が互いに相違す
るように構成されたことを特徴とする特許請求の
範囲第１項に記載の光フアイバ線路の監視方式。 ３ 入射手段から入射される光の波長がこの光フ
アイバ線路に伝送される主通信情報を伝搬する光
の波長と異なる波長であつて、反射手段は上記入
射される光の波長を上記主通信情報を伝搬する光
の波長から分別して反射するように構成されたこ
とを特徴とする特許請求の範囲第１項または第２
項に記載の光フアイバ線路の監視方式。 ４ 反射手段が操作により到来光を透過するモー
ドに切替えられるように構成されたことを特徴と
する特許請求の範囲第１項ないし第３項のいずれ
かに記載の光フアイバ線路の監視方式。[Claims] 1. An optical fiber line to be monitored is provided with an input means for inputting light into the optical fiber line at one end thereof, and the light is reflected at the other end of the optical fiber line so that the reflectance is set to a specific frequency. 1. A monitoring system for an optical fiber line, comprising: a reflecting means configured to change at a constant frequency, and a detecting means at one end for detecting a component modulated at the specific frequency from light arriving from the other end. 2. The optical fiber line is an optical fiber line that is branched into two or more parts, and each branched end is provided with a reflecting means, and the specific frequencies of the respective other ends are configured to be different from each other. A method for monitoring an optical fiber line according to claim 1. 3. The wavelength of the light incident from the input means is different from the wavelength of the light that propagates the main communication information transmitted to this optical fiber line, and the reflection means converts the wavelength of the light incident on the optical fiber line into the main communication information. Claims 1 or 2 are configured to reflect the light separately from the wavelength of the light that propagates.
The optical fiber line monitoring method described in Section 1. 4. The optical fiber line monitoring system according to any one of claims 1 to 3, wherein the reflecting means is configured to be switched to a mode in which incoming light is transmitted through operation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56171925A JPS5871740A (en) | 1981-10-26 | 1981-10-26 | Monitoring system for optical fiber line |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56171925A JPS5871740A (en) | 1981-10-26 | 1981-10-26 | Monitoring system for optical fiber line |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5871740A JPS5871740A (en) | 1983-04-28 |
| JPS6322694B2 true JPS6322694B2 (en) | 1988-05-12 |
Family
ID=15932384
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56171925A Granted JPS5871740A (en) | 1981-10-26 | 1981-10-26 | Monitoring system for optical fiber line |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5871740A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01211263A (en) * | 1988-02-17 | 1989-08-24 | Sony Corp | Recording/playback device |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000358261A (en) | 1999-06-16 | 2000-12-26 | Nec Corp | Optical cross-connector, optical network unit and connection state monitor method |
| JP2015170871A (en) * | 2014-03-04 | 2015-09-28 | 富士通株式会社 | Optical transmission system and optical receiver |
-
1981
- 1981-10-26 JP JP56171925A patent/JPS5871740A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01211263A (en) * | 1988-02-17 | 1989-08-24 | Sony Corp | Recording/playback device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5871740A (en) | 1983-04-28 |
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