JPH0634894A - Excessive light cutting-off device - Google Patents

Excessive light cutting-off device

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Publication number
JPH0634894A
JPH0634894A JP21241292A JP21241292A JPH0634894A JP H0634894 A JPH0634894 A JP H0634894A JP 21241292 A JP21241292 A JP 21241292A JP 21241292 A JP21241292 A JP 21241292A JP H0634894 A JPH0634894 A JP H0634894A
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Prior art keywords
light
optical
means
main transmission
transmission line
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JP21241292A
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Japanese (ja)
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JP2610211B2 (en )
Inventor
Toru Shiraki
Tsugio Tokumasu
次雄 徳増
徹 白木
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Fuji Elelctrochem Co Ltd
富士電気化学株式会社
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Abstract

PURPOSE:To prevent excessive light whose intensity exceeds a prescribed level from reaching optical circuit components of an optical measuring instrument, an optical communication device, etc. CONSTITUTION:This excessive light cutting-off device is equipped with an optical branching means 2 which takes part of light propagated on a main transmission line 1 as monitor light by a constant intensity rate, an optical delay means 3 which delays the propagation of the light on the main transmission line passed through the optical branching means 3, an optical switch 4 which cuts off the propagation of the light on the main transmission line passed through the optical delay means 3, a photodetecting means 6 which generates an electric signal corresponding to the intensity of the monitor light taken out by the optical branching means 2, a comparing means 8 which discriminates the level of the output of the photodetecting means 6, and a driving means 9 which turns OFF the optical switch 4 when the comparing means 8 detects the output of the photodetecting means 6 exceeding the set level.

Description

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

【0001】 [0001]

【産業上の利用分野】この発明は、光学測定装置や光通信装置などの光回路部品に規定レベル以上の強度の過大光が及ぶのを防止するための過大光遮断装置に関する。 BACKGROUND OF THE INVENTION This invention relates to excessive light blocking device for preventing an excessive light of specified level or more intensity to the optical circuit components such as optical measuring device and an optical communication device spans.

【0002】 [0002]

【従来の技術】光回路技術の進歩に伴い、光通信などに用いられるレーザ光源の強度が次第に大きくなってきており、光増幅器が異常発振を起こしたときに規定レベルを超える過大な強度の光が伝播していまい、光アイソレータ、受光素子などの光部品を破壊することがある。 With the progress of the Prior Art Optical circuit technology, it has become gradually larger intensity of the laser light source used in optical communications, excessive intensity above a prescribed level when the optical amplifier caused the abnormal oscillation light there Mai has propagated, optical isolators, which may destroy the optical components such as light receiving elements. そのため、このような過大光から光回路部品を保護する必要性がでてきたが、従来この目的に合致する適当な光遮断装置はなかった。 Therefore, such is excessive need to protect optical circuit components from light came out, there was no suitable light blocking device that matches a conventional purpose.

【0003】 [0003]

【発明が解決しようとする課題】光回路上において伝播する光の強度を調節するための機器として光減衰器がある。 There is an optical attenuator as a device for adjusting the intensity of the light propagating in the optical circuit on the [0005]. この光減衰器を光回路中に挿入しておくことで、過大な光が後段に伝播するのをある程度防ぐ効果があるが、これは通常状態での正常なレベルの光に対しても減衰作用が及ぶので、電気回路における過電流遮断器や過電圧遮断器のように過大な入力に対してのみ作動する遮断器とは本質的に異なる。 By keeping inserting the optical attenuator in the optical circuit, but excessive light to some extent prevent the effect from being propagated to the subsequent stage, which damping action against normal levels of light in the normal state since spans essentially different from the circuit breaker to operate only for the excessive input as overcurrent breakers and overvoltage breaker in an electrical circuit.

【0004】この発明は前述した従来の問題点に鑑みなされたもので、その目的は、光伝送路上を伝播する光の強度が規定レベルを超えたときに作動して光伝播を遮断し、通常状態ではできるだけ光を減衰させないようにした過大光遮断装置を提供することにある。 [0004] The present invention has been made in consideration of the conventional problems described above, its objective is to operate when the intensity of the light propagating in the optical transmission line exceeds a specified level to block the light propagation, usually to provide excessive light shielding apparatus that does not attenuate as much as possible light in the state.

【0005】 [0005]

【課題を解決するための手段】この発明の過大光遮断装置は、主伝送路を伝播する光の一部を一定強度比率だけモニター光として取り出す光分岐手段と、この光分岐手段を経た主伝送路上の光の伝播を遅延させる光遅延手段と、この光遅延手段を経た主伝送路上の光の伝播を遮断するための光スイッチと、前記光分岐手段により取り出した前記モニター光の強度に対応した電気信号を発生する光検出手段と、この光検出手段の出力をレベル弁別する比較手段と、この比較手段により前記光検出手段の出力が設定レベルを超えたことが検出されたときに前記光スイッチを遮断状態にする駆動手段とを備えたものである。 Means for Solving the Problems] excessive light blocking device of the present invention, a light branching means for extracting part of the light only as a monitor light constant intensity ratio propagating main transmission path, the main transmission via the optical branching unit an optical delay means for delaying the propagation of light path, an optical switch for blocking the propagation of light of the main transmission line passing through the optical delay means, corresponding to the intensity of the monitor light extracted by the light branching means the optical switch when light detecting means for generating an electrical signal, which is possible comparison means for level discrimination output of the light detection means, an output of said light detecting means by the comparing means exceeds the set level has been detected is obtained by a drive means for blocking state.

【0006】 [0006]

【作用】厳密に言うと前記光分岐手段と前記光遅延手段を主伝送路中に挿入することで主伝送路に僅かな損失を与えるが、この伝送損失は無視することができる程度に充分小さくすることができる。 [Action] give strictly speaking slight loss in the main transmission path by inserting the optical delay means and said light branching means to the main transmission line, but small enough to the extent this transmission loss can be ignored can do. 主伝送路を伝播する光の強度が前記光検出手段と前記比較手段とによって常時監視されており、設定レベルを超える過大な強度の光が検出されると、前記駆動回路によって前記光スイッチが遮断状態にされる。 Are constantly monitored intensity of the light propagating in the main transmission path by said comparing means and said light detecting means, the light of excessive intensity above a set level is detected, the optical switch is cut off by the drive circuit It is to the state. 過大光が伝播した時点から光スイッチが遮断するまでにはある程度の遅れ時間が生じるが、前記光分岐手断と光スイッチとの間に挿入された前記光遅延手段がその応答遅れを吸収する。 Excessive light occurs some delay time from the time propagated to the optical switch is cut off, but the optical add hands sectional and inserted the optical delay means between the optical switch to absorb the response delay.

【0007】 [0007]

【実施例】この発明の一実施例による過大光遮断装置の概略構成を図1に示している。 EXAMPLES shows a schematic structure of an excessive light shielding device according to an embodiment of the present invention in FIG. 主伝送路を構成する入力側光ファイバ1と出力側光ファイバ5との間に本発明の過大光遮断装置を構成している光分岐器2と遅延用光ファイバ3と光スイッチ4とがこの順に挿入されている。 An optical splitter 2 and the delay optical fiber 3 constituting the excessive light blocking device of the present invention between the input optical fiber 1 and the output-side optical fiber 5 constituting the main transmission line and the optical switch 4 is the It is inserted in the order.

【0008】光分岐器2は、主伝送路を伝播する光の強度測定用のモニター光を主伝送路から分岐して取り出すためのもので、入力光の偏光状態に関わりなく入力光強度の一定比率の光をモニター光として分岐出力するように構成する。 [0008] optical splitter 2, a monitor light for intensity measurement of the light propagating in the main transmission path provided for taking out branches from the main transmission path, certain input light intensity regardless of the polarization state of the input light configured to branch outputs the ratio of the light as a monitor light. 分岐光の強度比率はできるだけ小さい方がよく、例えば0.5%程度が好ましい。 Intensity ratio of the branched light may have as small as possible, for example, is preferably about 0.5%. 図示した実施例の光分岐器2は、入力側光ファイバ1のファイバコリメータ21と遅延用光ファイバ3の側のファイバコリメータ22との間に、複屈折板23と、主光軸に対して傾斜した誘電体薄膜付きガラス板24とを配設したものである。 Optical splitter 2 of the illustrated embodiment, between the fiber collimator 21 of the input optical fiber 1 and the side fiber collimator 22 of the optical delay fiber 3, the birefringent plate 23, inclined with respect to the main optical axis the one in which a dielectric thin film-coated glass plate 24 is disposed. また、複屈折板の光線軸は光の誘電体薄膜付ガラス板への入射面に対して45°傾いてある。 Also, light axis of the birefringent plate are inclined 45 ° with respect to the plane of incidence of the light of the dielectric thin film coated glass plate. このような偏光ビームスプリッタ式の光分岐器2に限定されるものではなく、よく知られた光ファイバカプラを前記と同じ機能の光分岐器として使用することができる。 Such polarizing beam splitter formula is not limited to optical splitter 2 can use well-known optical fiber coupler as optical divider having the same function as described above.

【0009】入力側光ファイバ1を伝播する光の99% [0009] 99% of the light propagating in the input-side optical fiber 1
以上は、光分岐器2を経て遅延用光ファイバ3に伝わる。 Above, via the optical splitter 2 transmitted to the delaying optical fiber 3. この遅延用光ファイバ3は、以下に説明するだけの伝播時間を稼ぐために挿入したもので、必要な遅延時間に合せてその長さが決まる。 The delaying optical fiber 3, which was inserted to make only propagation time will be described below, the length is determined in accordance with the delay time required.

【0010】光スイッチ4は、通常時は損失なく出力側光ファイバ5に入力光を伝え、後述する駆動回路からの信号に応答して遮断モードになり、入力光が出力側光ファイバ5に伝わるのを完全に遮断する。 [0010] The optical switch 4, when normally convey input light to the output side optical fiber 5 without loss, becomes blocked mode in response to a signal from the drive circuit to be described later, the input light transmitted to the output-side optical fiber 5 to completely block the. この実施例の光スイッチ4は、遅延用光ファイバ3側のファイバコリメータ41と出力側光ファイバ5のファイバコリメータ4 The optical switch 4 in this embodiment, the fiber collimator 4 of the output side optical fiber 5 and the fiber collimator 41 of the optical delay fiber 3 side
2との間に、複屈折板43と、ファラデー効果素子板4 Between 2 and birefringent plate 43, the Faraday effect element plate 4
4と、半波長板47と、複屈折板45を配設したもので、よく知られているようにファラデー効果素子板44 4, a half-wave plate 47, which was disposed through the birefringent plate 45, as is well-known Faraday effect element plate 44
に付設した励磁器46のコイルに印加する信号で光スイッチ4をオン・オフするようになっている。 Is adapted to turn on and off the light switch 4 by a signal applied to the coil of the exciter 46 is attached to. この他にも各種の方式、構成の光スイッチを用いることができる。 Other various methods can also be used an optical switch configuration.
すなわち、例えば、前記のファラデー効果素子板と半波長板に替えてPLZTなどの電気光学素子を用いたものや、シャッターや反射板をアクチュエータで機械的に変位させるものなどがある。 That is, for example, or those using electro-optical element such as a PLZT instead of the Faraday effect element plate and the half-wave plate of said include those for mechanically displacing the shutter or reflector by an actuator. これらはいずれも本発明に適用することができる。 Any of these can be applied to the present invention.

【0011】前記の光分岐器2で分岐されたモニター光は光検出器6に受光され、検出器6からは光ファイバ1 [0011] monitor light branched by the optical splitter 2 is received by the optical detector 6, the optical fiber 1 from the detector 6
からの入力光の強度に対応した電気信号が出力される。 Electric signal corresponding to the intensity of the input light is outputted from.
光検出器6としては使用波長の光に対して必要な感度と精度が得られれば基本的にどのようなデバイスを使用してもよい。 It may be used basically any device as long obtain the required sensitivity and accuracy for light of wavelength used as the photodetector 6. 光通信に現在一般的に使用されているレーザ光の波長帯は1.31又は1.55マイクロメートルであるが、 Wavelength band of the laser beam which is currently commonly used in optical communications is a 1.31 or 1.55 micron,
この場合にはフォトダイオードや光導電素子などの半導体センサが好適である。 This is the case of the preferred semiconductor sensor such as a photodiode or photoconductive element.

【0012】光検出器6の出力信号はプリアンプ7で前処理されて比較手段たるコンパレータ8に入力され、適宜に設定された基準レベル信号Vsと比較される。 [0012] The output signal of the photodetector 6 is input to the comparison means serving the comparator 8 is pretreated with a preamplifier 7 and compared to appropriately set the criteria level signal Vs. 駆動回路9はコンパレータ8のレベル弁別出力を受けて光スイッチ4を駆動する。 Driving circuit 9 drives the optical switch 4 receives the level discrimination output of the comparator 8. つまり、光検出器6による検出レベルが基準レベル以下の場合は光スイッチ4はオンに保たれ、出力側光ファイバ5に入力光が伝播する。 That is, if the detected level by the photodetector 6 the following reference level optical switch 4 is kept turned on, the input light propagates to the output side optical fiber 5. 一方、 on the other hand,
入力光の検出レベルが基準レベルを超えるとコンパレータ8の出力が反転し、このとき光スイッチ4がオフとなり、出力側光ファイバ5への光伝播が遮断される。 Output is inverted in the detection level of the input light exceeds the reference level comparator 8, this time the optical switch 4 is turned off, light propagation is interrupted to the output side optical fiber 5.

【0013】入力光の強度が過大になってから光スイッチ4がオフになるまでにはある程度の応答遅れがあるが、遅延用光ファイバ3の遅延時間(光ファイバの長さ)を前記の応答時間より若干大きく設定しておく。 [0013] Although from the strength of the input light becomes excessive to the optical switch 4 is turned off there is a certain response delay, the delay time of the delay optical fiber 3 (length of the optical fiber) the response keep slightly larger than the time. そうすれば過大な入力光が出力側光ファイバ5に伝わることはない。 Never be so excessive input light transmitted to the output-side optical fiber 5. なお、前記応答時間が0.5〜20マイクロ秒であれば遅延用光ファイバ3の長さは100〜400 The length of the delay optical fiber 3 when the response time is 0.5 to 20 microseconds 100-400
0メートルとなる。 It is 0 meters.

【0014】 [0014]

【発明の効果】以上詳細に説明したように、この発明の過大光遮断装置によれば、主伝送路を伝播する光強度が通常レベル範囲に収まっていれば主伝送路に対してほとんど伝送損失を与えることがなく、主伝送路を伝播する光強度がなんらかの原因で増大して規定レベルを超えると、その過大光に応答して光スイッチがオフとなり、後段の光回路に過大光が伝わるのを確実に防止することができる。 As described [Effect Invention above in detail, according to the excessive light blocking device of the present invention, almost the transmission loss with respect to the main transmission path if the light intensity is only to fall to normal level range to propagate main transmission path without giving, exceeds a defined level light intensity propagating main transmission path is increased for some reason, the optical switch is turned off in response to the excessive light, excessive light is being transmitted to the subsequent stage of the optical circuit it is possible to reliably prevented.

【図面の簡単な説明】 BRIEF DESCRIPTION OF THE DRAWINGS

【図1】この発明の一実施例による過大光遮断装置の概略構成図である。 1 is a schematic configuration diagram of an excessive light shielding device according to an embodiment of the present invention.

【符号の説明】 DESCRIPTION OF SYMBOLS

1 入力側光ファイバ(主伝送路) 2 光分岐器(光分岐手段) 3 遅延用光ファイバ(光遅延手段) 4 光スイッチ 5 出力側光ファイバ 6 光検出器(光検出手段) 8 コンパレータ(比較手段) 9 駆動回路(駆動手段) 1 the input side optical fiber (main transmission path) 2 optical divider (optical branching means) 3 optical delay fiber (optical delay means) 4 optical switch 5 output optical fiber 6 photodetector (light detector) 8 comparator (comparative means) 9 driving circuit (driving means)

Claims (1)

    【特許請求の範囲】 [The claims]
  1. 【請求項1】 主伝送路を伝播する光の一部を一定強度比率だけモニター光として取り出す光分岐手段と、この光分岐手段を経た主伝送路上の光の伝播を遅延させる光遅延手段と、この光遅延手段を経た主伝送路上の光の伝播を遮断するための光スイッチと、前記光分岐手段により取り出した前記モニター光の強度に対応した電気信号を発生する光検出手段と、この光検出手段の出力をレベル弁別する比較手段と、この比較手段により前記光検出手段の出力が設定レベルを超えたことが検出されたときに前記光スイッチを遮断状態にする駆動手段とを備えたことを特徴とする過大光遮断装置。 An optical splitting means for taking out the method according to claim 1 Some of the light propagating in the main transmission path only as a monitor light constant intensity ratio, an optical delay means for delaying the propagation of light of the main transmission line passing through the light branching means, an optical switch for blocking the optical delay means light propagation of the main transmission line passing through a light detecting means for generating an electrical signal corresponding to the intensity of the monitor light extracted by the optical branching unit, the photodetection comparing means for level discrimination output means further comprising a drive means for the cut-off state the optical switch when the output of said light detecting means exceeds a set level is detected by the comparison means excessive light blocking device comprising.
JP21241292A 1992-07-17 1992-07-17 Excessive light blocking device Expired - Lifetime JP2610211B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
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Application Number Priority Date Filing Date Title
JP21241292A JP2610211B2 (en) 1992-07-17 1992-07-17 Excessive light blocking device

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JPH0634894A true true JPH0634894A (en) 1994-02-10
JP2610211B2 JP2610211B2 (en) 1997-05-14

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01293328A (en) * 1988-05-20 1989-11-27 Nec Corp Polarization diversity optical receiver
JPH07306390A (en) * 1994-05-12 1995-11-21 Fuji Elelctrochem Co Ltd Polarization plane changeover device and optical switch using the same
US5521741A (en) * 1994-05-09 1996-05-28 Fdk Corporation Polarization plane switch and optical switching device using the same
US7488925B2 (en) 2003-11-17 2009-02-10 Nec Corporation Light control apparatus having a device for controlling the input signal light of an optical transmission path

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62245828A (en) * 1986-04-18 1987-10-27 Nippon Telegr & Teleph Corp <Ntt> Method and apparatus for switching optical fiber without hit
JPH01266505A (en) * 1988-04-18 1989-10-24 Nec Corp Monitoring device

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62245828A (en) * 1986-04-18 1987-10-27 Nippon Telegr & Teleph Corp <Ntt> Method and apparatus for switching optical fiber without hit
JPH01266505A (en) * 1988-04-18 1989-10-24 Nec Corp Monitoring device

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH01293328A (en) * 1988-05-20 1989-11-27 Nec Corp Polarization diversity optical receiver
JP2658180B2 (en) * 1988-05-20 1997-09-30 日本電気株式会社 Polarization diversity optical receiver
US5521741A (en) * 1994-05-09 1996-05-28 Fdk Corporation Polarization plane switch and optical switching device using the same
JPH07306390A (en) * 1994-05-12 1995-11-21 Fuji Elelctrochem Co Ltd Polarization plane changeover device and optical switch using the same
US7488925B2 (en) 2003-11-17 2009-02-10 Nec Corporation Light control apparatus having a device for controlling the input signal light of an optical transmission path

Also Published As

Publication number Publication date Type
JP2610211B2 (en) 1997-05-14 grant

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