JPH05327616A - Optical signal receiver - Google Patents
Optical signal receiverInfo
- Publication number
- JPH05327616A JPH05327616A JP4135208A JP13520892A JPH05327616A JP H05327616 A JPH05327616 A JP H05327616A JP 4135208 A JP4135208 A JP 4135208A JP 13520892 A JP13520892 A JP 13520892A JP H05327616 A JPH05327616 A JP H05327616A
- Authority
- JP
- Japan
- Prior art keywords
- light
- signal
- local
- receiving element
- light source
- 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.)
- Granted
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は光通信装置に利用する。
特に、光信号受信装置の信号光待機時のコールドスター
ト制御技術に関する。コールドスタートとは待機時に主
要電源を断にしておき、受信信号が到来すると自動的に
起動する方式をいう。BACKGROUND OF THE INVENTION The present invention is used in an optical communication device.
In particular, the present invention relates to a cold start control technique for a signal light standby of an optical signal receiving device. Cold start is a method in which the main power supply is turned off during standby, and it automatically starts when a received signal arrives.
【０００２】[0002]
【従来の技術】光信号受信装置において、入力された信
号光を光ヘテロダイン方式では、中間信号に、光ホモダ
イン方式ではベースバンド信号に変換する。そのため、
入力信号の周波数に対応したローカル光源の周波数制御
が必要となる。ローカル光源は一般的にレーザダイオー
ド（以下、ＬＤと呼ぶ）が用いられ、周波数を変化させ
るパラメータとしてＬＤバイアス電流および温度があ
る。2. Description of the Related Art In an optical signal receiving apparatus, the input signal light is converted into an intermediate signal in the optical heterodyne system and into a baseband signal in the optical homodyne system. for that reason,
It is necessary to control the frequency of the local light source corresponding to the frequency of the input signal. A laser diode (hereinafter referred to as an LD) is generally used as a local light source, and an LD bias current and a temperature are parameters for changing the frequency.
【０００３】この周波数制御はＡＦＣと呼ばれ、応答速
度は一般的に数十Ｈｚから数百Ｈｚ程度に設定され、周
波数弁別部とＡＦＣ制御部およびローカル光源の電流バ
イアス可変部から構成される。ＡＦＣの周波数弁別範囲
は数ＧＨｚ程度であり、光源の波長ばらつきは通常これ
よりも大きく、電源投入時などに自動周波数引込みを必
要とする場合は、より広範囲なローカル光源の波長掃引
機能を持ったコールドスタート制御が行われる。This frequency control is called AFC, and the response speed is generally set to about several tens Hz to several hundreds Hz, and it is composed of a frequency discriminating section, an AFC control section and a current bias variable section of the local light source. The frequency discrimination range of AFC is about several GHz, and the wavelength variation of the light source is usually larger than this. When automatic frequency pulling is required at the time of turning on the power, the wavelength sweeping function of the local light source has a wider range. Cold start control is performed.
【０００４】図６を参照して従来例を説明する。図６は
従来例のコールドスタート制御のアルゴリズムを説明す
るフローチャートである。コールドスタート制御回路に
電源が投入されると、ＬＤバイアス電流および温度は初
期値に設定される（Ｓ１）。このとき、ＩＦ信号がすで
に検出されていれば掃引を停止し、ＡＦＣをＯＮにする
（Ｓ２→Ｓ８）。さらに、ＩＦ信号が検出され続けてい
れば、ＡＦＣの動作をＩＦ信号が非検出となるまで、す
なわち、受信が終了するまで続行させる（Ｓ９）。ま
た、受信が終了したか、あるいは掃引過程でＩＦ信号を
見失えばＡＦＣをＯＦＦにし（Ｓ１０）、処理をＳ３に
移す。A conventional example will be described with reference to FIG. FIG. 6 is a flow chart for explaining a conventional cold start control algorithm. When the cold start control circuit is powered on, the LD bias current and temperature are set to initial values (S1). At this time, if the IF signal has already been detected, the sweep is stopped and the AFC is turned on (S2 → S8). Further, if the IF signal is continuously detected, the AFC operation is continued until the IF signal is not detected, that is, until the reception is completed (S9). If the reception is completed or if the IF signal is lost in the sweep process, AFC is turned off (S10), and the process proceeds to S3.
【０００５】ＩＦ信号が初めから非検出の場合は、ＬＤ
バイアス電流を１周期掃引させたか否か判断し（Ｓ
３）、１周期掃引させていれば、ＬＤ温度を１ステップ
変化させ（Ｓ４）、１周期掃引させていなければ１周期
掃引する（Ｓ５）。次に、ＬＤ温度を１ステップ変化さ
せたか否か判断し、１ステップ変化させていなければ処
理をＳ２以降に戻す（Ｓ６）。１ステップ変化させてい
ればその処理が予め設定されていた規定回数繰り返され
たか否かを判断し、規定回数に満たなければ処理をＳ１
以降にもどし、規定回数に達していればコールドスター
ト制御を停止させる（Ｓ７）。If the IF signal is not detected from the beginning, LD
It is determined whether or not the bias current is swept for one cycle (S
3) If it is swept for one cycle, the LD temperature is changed by one step (S4), and if not swept for one cycle, one cycle is swept (S5). Next, it is judged whether or not the LD temperature is changed by one step, and if not changed by one step, the process is returned to S2 and subsequent steps (S6). If it is changed by one step, it is determined whether or not the process has been repeated a preset number of times set in advance.
After that, the cold start control is stopped if the number of times reaches the specified number (S7).
【０００６】[0006]
【発明が解決しようとする課題】このようにコールドス
タート制御回路が動作を開始すると、ローカルＬＤのバ
イアス電流と温度を掃引させて中間周波（以下、ＩＦと
呼ぶ）信号を検出し、その後にＡＦＣを開始する。ここ
で送信装置の停止等で信号光が来ないにも関わらず、受
信装置に設けられているコールドスタート制御回路が動
作している場合は、ローカルＬＤのバイアス電流および
温度を繰り返しＩＦ信号が検出されるまで掃引するた
め、ローカルＬＤ素子の劣化を早める恐れがある。これ
を防止するために、繰り返し掃引の回数を予め設定して
おき、予定の回数を掃引してもＩＦ信号が検出されない
ときコールドスタート制御を停止する。ただし、この場
合は、信号光の送出を確認して手動でコールドスタート
制御の再起動をかけてやる必要がある。なぜなら信号光
の送出を受信装置で検出し自動で再起動をかけようとし
た場合は、受光素子は信号光に比べてはるかに強いロー
カル光源からの光を常時受けているため、そのままでは
受光素子の電流変化から信号光の有無を識別するのは困
難であり、新たに信号光の検出回路を付加すると信号光
分岐による受信感度の劣化や実装規模の増大を招く恐れ
があった。When the cold start control circuit thus starts its operation, the bias current and temperature of the local LD are swept to detect an intermediate frequency (hereinafter referred to as IF) signal, and then the AFC is performed. To start. Here, when the cold start control circuit provided in the receiving device is operating although the signal light does not come due to the stop of the transmitting device or the like, the IF signal is detected by repeating the bias current and temperature of the local LD. Since the sweep is performed until it is removed, there is a possibility that the local LD element will be deteriorated more quickly. In order to prevent this, the number of repeated sweeps is set in advance, and the cold start control is stopped when the IF signal is not detected even after the predetermined number of sweeps. However, in this case, it is necessary to confirm the transmission of the signal light and manually restart the cold start control. This is because if the receiver detects the output of the signal light and tries to restart automatically, the light receiving element always receives light from the local light source, which is much stronger than the signal light. It is difficult to discriminate the presence or absence of signal light from the change in the current, and if a signal light detection circuit is newly added, there is a risk of deterioration of receiving sensitivity due to signal light branching and an increase in mounting scale.
【０００７】本発明は、このような背景に行われたもの
であり、コールドスタート制御における信号光の検出を
受信感度の劣化や装置規模を増大させることのない簡易
な回路で実現できるコールドスタート制御装置を提供す
ることを目的とする。The present invention has been made against such a background, and the cold start control can realize the detection of the signal light in the cold start control by a simple circuit which does not deteriorate the receiving sensitivity or increase the device scale. The purpose is to provide a device.
【０００８】[0008]
【課題を解決するための手段】本発明は、コヒーレント
光を発生するローカル光源と、このローカル光源の電源
回路と、このコヒーレント光と受信信号光を混合する手
段と、この手段の出力光を電気信号に変換する受光素子
と、この受光素子を動作状態にバイアスするバイアス電
流供給回路とを備えた光信号受信機である。According to the present invention, a local light source for generating coherent light, a power supply circuit for the local light source, a means for mixing the coherent light and the received signal light, and an output light of this means are electrically connected. The optical signal receiver includes a light receiving element for converting into a signal, and a bias current supply circuit for biasing the light receiving element into an operating state.
【０００９】ここで、本発明の特徴は、前記電源回路に
は、受信待機状態で前記ローカル光源を滅灯状態に制御
する制御回路が接続され、この制御回路は、前記バイア
ス電流供給回路の出力電流が所定値を越えたときに自動
的に前記ローカル光源を点灯させる制御手段を含むこと
である。Here, a feature of the present invention is that the power supply circuit is connected to a control circuit for controlling the local light source to be turned off in a reception standby state, and the control circuit outputs the output of the bias current supply circuit. A control means for automatically turning on the local light source when the current exceeds a predetermined value is included.
【００１０】また、前記受光素子の出力電気信号に受信
信号光の中間周波信号が含まれていることを検出する手
段と、この手段の検出出力がないときに前記電源回路を
制御して前記ローカル光源を滅灯させる制御手段とを備
えることが望ましい。Further, means for detecting that the output electric signal of the light receiving element includes the intermediate frequency signal of the received signal light, and the power supply circuit is controlled when the detection output of this means is absent. It is desirable to provide a control means for turning off the light source.
【００１１】[0011]
【作用】受光素子と、この受光素子にバイアスを供給す
る端子との間に電流電圧変換素子を介挿し、ローカル光
源の発光を停止させて待機する。ここで信号光が到来す
ると、受光素子のバイアス電流が変化する。この電流電
圧変換素子の電位変化をコールドスタート制御回路は起
動信号としてコールドスタート制御を開始する。このよ
うに信号光が検出された場合には、コールドスタート制
御回路は受信経路をコヒーレント受信用に切り替えてロ
ーカル光源を点灯させ、到来した信号光の復調を行う。The current-voltage conversion element is inserted between the light receiving element and the terminal for supplying the bias to the light receiving element, and the light emission of the local light source is stopped to stand by. When the signal light arrives, the bias current of the light receiving element changes. The cold start control circuit starts cold start control by using the potential change of the current-voltage conversion element as a start signal. When signal light is detected in this way, the cold start control circuit switches the reception path for coherent reception, lights the local light source, and demodulates the incoming signal light.
【００１２】その間、信号光中のＩＦ信号をコールドス
タート制御回路の周波数弁別部は検出し続けており、こ
のＩＦ信号が非検出となったときには、コールドスター
ト制御回路はローカル光源を滅灯させ光信号受信機を待
機状態に復帰させる。During that time, the frequency discriminating section of the cold start control circuit continues to detect the IF signal in the signal light, and when this IF signal becomes non-detection, the cold start control circuit turns off the local light source and lights it. Return the signal receiver to the standby state.
【００１３】[0013]
【実施例】本発明第一実施例の構成を図１および図２を
参照して説明する。図１は本発明第一実施例の全体構成
図である。図２は本発明第一実施例装置の構成図であ
る。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an overall configuration diagram of the first embodiment of the present invention. FIG. 2 is a block diagram of the device of the first embodiment of the present invention.
【００１４】本発明は、コヒーレント光を発生するロー
カル光源であるローカルＬＤ１２と、このローカルＬＤ
１２の電源回路であるＬＤ電源回路２７と、このコヒー
レント光と受信信号光を混合する手段である光フロント
エンド回路３と、この光フロントエンド回路３の出力光
を電気信号に変換する受光素子５および６と、この受光
素子５および６を動作状態にバイアスするバイアス電流
供給回路１７とを備えた光信号受信機である。The present invention relates to a local LD 12 which is a local light source for generating coherent light, and this local LD.
The LD power supply circuit 27 which is the power supply circuit of 12, the optical front end circuit 3 which is means for mixing the coherent light and the received signal light, and the light receiving element 5 which converts the output light of the optical front end circuit 3 into an electric signal. And 6 and a bias current supply circuit 17 for biasing the light receiving elements 5 and 6 into an operating state.
【００１５】ここで、本発明の特徴は、ＬＤ電源回路２
７には、受信待機状態でローカルＬＤ１２を滅灯状態に
制御する制御回路であるコールドスタート制御回路１１
が接続され、このコールドスタート制御回路１１は、バ
イアス電流供給回路１７の出力電流が所定値を越えたと
きに自動的にローカルＬＤ１２を点灯させる制御手段で
あるコールドスタート制御部２３を含むことである。Here, the feature of the present invention is that the LD power supply circuit 2 is provided.
7 is a cold start control circuit 11 which is a control circuit for controlling the local LD 12 to be in the extinguished light state in the reception standby state.
Is connected, and the cold start control circuit 11 includes a cold start control section 23 which is a control means for automatically lighting the local LD 12 when the output current of the bias current supply circuit 17 exceeds a predetermined value. ..
【００１６】また、受光素子５および６の出力電気信号
に受信信号光の中間周波信号が含まれていることを検出
する手段である周波数弁別部２１と、この周波数弁別部
２１の検出出力がないときにＬＤ電源回路２７を制御し
てローカルＬＤ１２を滅灯させる制御手段とを備えてい
る。Further, there is no frequency discriminating portion 21 which is means for detecting that the output electric signals of the light receiving elements 5 and 6 include the intermediate frequency signal of the received signal light, and there is no detection output of the frequency discriminating portion 21. And a control means for controlling the LD power supply circuit 27 to extinguish the local LD 12 at times.
【００１７】次に、本発明第一実施例装置の動作を図３
を参照して説明する。図３は本発明第一実施例の動作を
示すフローチャートである。本発明第一実施例装置は、
光ヘテロダイン受信方式の受信装置にコールドスタート
制御回路１１を含むコールドスタート制御機能を設けた
構成である。光入力端子１から入力された信号光の偏波
状態は、偏波制御器２で最適な状態に調整される。ロー
カルＬＤ１２の強度雑音を避けるために、二つの受光素
子５および６を用いて同じパワーかつ互いに逆相で受信
する。Next, the operation of the apparatus according to the first embodiment of the present invention will be described with reference to FIG.
Will be described. FIG. 3 is a flow chart showing the operation of the first embodiment of the present invention. The first embodiment device of the present invention is
This is a configuration in which a cold start control function including a cold start control circuit 11 is provided in a receiver of the optical heterodyne reception system. The polarization state of the signal light input from the optical input terminal 1 is adjusted to the optimum state by the polarization controller 2. In order to avoid the intensity noise of the local LD 12, two light receiving elements 5 and 6 are used to receive with the same power and opposite phases.
【００１８】この受信装置の電源が投入されると、切替
スイッチ４は受光素子５と電流電圧変換素子７を接続す
る経路に設定される。このとき、ローカルＬＤ１２のロ
ーカル光はＯＦＦである（Ｓ１１）。本発明第一実施例
では、この電流電圧変換素子７に抵抗を用いた。信号光
が非検出のときは、電流電圧変換素子７の切替スイッチ
４側に接続されている端子１６の電位は、受光素子５に
電流がほとんど流れていないため、受光素子バイアス端
子１５2 の電位にほぼ等しい。信号光が検出されると、
受光素子５に電流が流れ、電流電圧変換素子７の切替ス
イッチ４側に接続されている端子１６の電位が変化す
る。When the power of this receiving device is turned on, the changeover switch 4 is set to the path connecting the light receiving element 5 and the current-voltage conversion element 7. At this time, the local light of the local LD 12 is OFF (S11). In the first embodiment of the present invention, a resistor is used for the current-voltage conversion element 7. When the signal light is not detected, the potential of the terminal 16 connected to the changeover switch 4 side of the current-voltage conversion element 7 is almost the same as that of the light-receiving element bias terminal 15 2 because almost no current flows in the light-receiving element 5. Is almost equal to. When the signal light is detected,
A current flows through the light receiving element 5, and the potential of the terminal 16 connected to the changeover switch 4 side of the current-voltage conversion element 7 changes.
【００１９】コヒーレント光受信方式の一つである光ヘ
テロダイン受信方式は、高受信感度特性を有するため受
信レベルが非常に低い場合も考慮する必要がある。ここ
では、受信レベルを−５０ｄＢｍまで考え、受光素子５
の量子効率１では約１０ｎＡの電流が流れ、電流電圧変
換素子７の抵抗値を１００ＭΩとして約１Ｖの電圧が変
化する。逆に、受信レベルが非常に高い場合は、受光素
子バイアス端子１５2の電位と電流電圧変換素子７の値
によって電流の飽和が起こり、切替スイッチ４側に接続
されている端子１６の電位はほぼ０Ｖになる。この場合
は、受光素子６にも受光素子５と同様な光パワーを受け
ているため電流が流れるが、受光素子６に流れる電流が
受光素子５に流れる電流と異なる場合でも、受光素子用
負荷抵抗８が電流電圧変換素子７の抵抗値と比較しては
るかに小さいため、受光素子５および６の接続点の電位
変化は無視でき、ほぼ０Ｖと考えてよい。The optical heterodyne receiving method, which is one of the coherent optical receiving methods, has a high receiving sensitivity characteristic, so that it is necessary to consider the case where the receiving level is very low. Here, considering the reception level up to −50 dBm, the light receiving element 5
A current of about 10 nA flows at a quantum efficiency of 1, and a voltage of about 1 V changes when the resistance value of the current-voltage conversion element 7 is 100 MΩ. On the other hand, when the reception level is very high, the electric potential of the light receiving element bias terminal 15 2 and the value of the current-voltage conversion element 7 cause saturation of the current, and the electric potential of the terminal 16 connected to the changeover switch 4 side is almost the same. It becomes 0V. In this case, a current flows through the light receiving element 6 because it receives the same optical power as the light receiving element 5, but even if the current flowing through the light receiving element 6 is different from the current flowing through the light receiving element 5, the load resistance for the light receiving element Since 8 is much smaller than the resistance value of the current-voltage conversion element 7, the potential change at the connection point of the light-receiving elements 5 and 6 can be ignored and can be considered to be almost 0V.
【００２０】このように電流電圧変換素子７の切替スイ
ッチ４側に接続されている端子１６の電位の範囲は受光
素子バイアス端子１５2 の電位から０Ｖまでであり、適
当な電流電圧変換素子７の抵抗値および受光素子バイア
ス端子１５2 の電位を選択することにより制御信号とし
て直接コールドスタート制御回路１１に取り込むことが
可能である。この制御信号をもとに、信号光の識別がな
され、信号光があると判断された場合は（Ｓ１２）、受
光素子バイアス端子１５1 と受光素子５を接続する経路
に切替スイッチ４は切替られ、ローカルＬＤ１２がＯＮ
となって、コールドスタート制御が開始される（Ｓ１
３）。他の動作は、従来例と同様なので説明は省略す
る。ただし、Ｓ６で“ＹＥＳ”と判断したときおよびＳ
１０でＡＦＣがＯＦＦとなったときに本発明第一実施例
では、フローの始めに戻り、ローカルＬＤ１２を滅灯さ
せてＳ１１以降の処理を繰り返す。As described above, the range of the potential of the terminal 16 connected to the changeover switch 4 side of the current-voltage converting element 7 is from the potential of the light-receiving element bias terminal 15 2 to 0 V, and the appropriate current-voltage converting element 7 has By selecting the resistance value and the potential of the light receiving element bias terminal 15 2 , it is possible to directly take in the cold start control circuit 11 as a control signal. The signal light is identified based on this control signal, and when it is determined that there is signal light (S12), the changeover switch 4 is switched to the path connecting the light receiving element bias terminal 15 1 and the light receiving element 5. , Local LD12 is ON
Then, the cold start control is started (S1
3). The other operations are similar to those of the conventional example, and thus the description thereof is omitted. However, when "YES" is determined in S6 and S
When the AFC is turned off at 10, in the first embodiment of the present invention, the process returns to the beginning of the flow, the local LD 12 is extinguished, and the processing from S11 is repeated.
【００２１】図２に示すように、コールドスタート制御
回路１１では、コールドスタート制御部２３が、信号光
検出信号を電流電圧変換素子７から切替スイッチ４を介
して受け、ＬＤバイアス電流および温度を初期値に設定
した後に、主信号分岐１０からのＩＦ信号を周波数弁別
部２１で弁別し、ＩＦ信号が検出されない場合は切替ス
イッチ４″をコールドスタート制御部２３の側とし、Ｌ
Ｄバイアス電流可変部２５およびＬＤ温度可変部２６を
制御する。As shown in FIG. 2, in the cold start control circuit 11, the cold start control section 23 receives the signal light detection signal from the current-voltage conversion element 7 via the changeover switch 4 to initialize the LD bias current and temperature. After setting the value, the IF signal from the main signal branch 10 is discriminated by the frequency discriminating unit 21, and when the IF signal is not detected, the changeover switch 4 ″ is set to the cold start control unit 23 side, and L
The D bias current varying unit 25 and the LD temperature varying unit 26 are controlled.
【００２２】コールドスタート制御部２３は、周波数弁
別部２１よりＩＦ信号が検出された場合は、切替スイッ
チ４″をＡＦＣ制御部２４の側とし、ＬＤバイアス電流
可変部２５を制御してＡＦＣ動作を行う。受信が終了し
た場合またはノイズを信号光と誤認した場合など、ＩＦ
信号が途中で非検出となったときは、ローカルＬＤ１２
を滅灯させて待機状態に復帰する。When the IF signal is detected by the frequency discriminating unit 21, the cold start control unit 23 sets the changeover switch 4 ″ to the AFC control unit 24 side and controls the LD bias current varying unit 25 to perform the AFC operation. IF reception is completed or noise is mistaken for signal light, etc.
When the signal is not detected on the way, the local LD12
To turn off the light and return to the standby state.
【００２３】また、本発明第一実施例装置では、切替ス
イッチ４、電流電圧変換素子７、受光素子バイアス端子
１５2 を受光素子５の側に設けたが、受光素子６の側に
設ける構成とすることもできる。Further, in the first embodiment of the present invention, the changeover switch 4, the current-voltage conversion element 7, and the light-receiving element bias terminal 15 2 are provided on the light-receiving element 5 side, but they are provided on the light-receiving element 6 side. You can also do it.
【００２４】次に、本発明第二実施例を図４および図５
を参照して説明する。図４は本発明第二実施例の全体構
成図である。図５は本発明第二実施例装置の構成図であ
る。本発明第二実施例は、偏波ダイバーシティ形コヒー
レント光受信方式の受信装置にコールドスタート制御回
路１１′を含むコールドスタート制御機能を設けた構成
である。偏波ダイバーシティ形コヒーレント光受信方式
では、信号光がいかなる偏波状態であっても安定して信
号を受信できるように、偏波ダイバーシティ光フロント
エンド回路５１において、信号光を直交した二つの偏波
に分離し、それぞれの信号光と二つに分けたローカル光
をそれぞれ混合し、２組の受光素子５、６および５′、
６′による光電気変換から復調までそれぞれ独立して行
われる。Next, a second embodiment of the present invention will be described with reference to FIGS.
Will be described. FIG. 4 is an overall configuration diagram of the second embodiment of the present invention. FIG. 5 is a block diagram of the apparatus of the second embodiment of the present invention. The second embodiment of the present invention is a configuration in which a cold start control function including a cold start control circuit 11 'is provided in a receiver of a polarization diversity type coherent optical receiving system. In the polarization diversity type coherent optical receiving system, the polarization diversity optical front end circuit 51 uses two polarization signals orthogonal to each other so that the signal light can be stably received regardless of the polarization state of the signal light. To separate the signal light and the local light split into two, respectively, to obtain two sets of light receiving elements 5, 6 and 5 ',
The photoelectric conversion by 6'to the demodulation are independently performed.
【００２５】コールドスタート制御のアルゴリズムは、
基本的には本発明第一実施例と同様である。受信装置の
電源が投入されると、切替スイッチ４および４′はそれ
ぞれ受光素子５および５′と電流電圧変換素子７および
７′を接続する経路に設定される。このとき、ローカル
光はＯＦＦである。信号光が非検出のときは、電流電圧
変換素子７の切替スイッチ４側に接続されている端子１
６の電位および電流電圧変換素子７′の切替スイッチ
４′側に接続されている端子１６′の電位は、それぞれ
受光素子バイアス端子１５2 および１５2 ′の電位にほ
ぼ等しい。信号光が検出されると、どのような偏波状態
においても少なくとも受光素子５または５′に電流が流
れ、端子１６または１６′の電位が変化する。これらの
端子１６または１６′からの電位変化をＯＲ回路６１に
入力して論理和を取ることによりＯＲ回路６１の出力側
から制御信号が得られる。The cold start control algorithm is
Basically, it is the same as the first embodiment of the present invention. When the power of the receiving device is turned on, the changeover switches 4 and 4'are set to the paths connecting the light receiving elements 5 and 5'and the current-voltage converting elements 7 and 7 ', respectively. At this time, the local light is off. When the signal light is not detected, the terminal 1 connected to the changeover switch 4 side of the current-voltage conversion element 7
The potential of 6 and the potential of the terminal 16 'connected to the changeover switch 4'of the current-voltage conversion element 7'are substantially equal to the potentials of the light-receiving element bias terminals 15 2 and 15 2 ', respectively. When signal light is detected, a current flows through at least the light receiving element 5 or 5'in any polarization state, and the potential of the terminal 16 or 16 'changes. A control signal is obtained from the output side of the OR circuit 61 by inputting the potential change from these terminals 16 or 16 'to the OR circuit 61 and taking the logical sum.
【００２６】受光素子バイアス端子１５2 、１５2 ′お
よび電流電圧変換素子７、７′の電位および抵抗値の設
定は本発明第一実施例と同様であるが、直交する二つの
偏波に分離された信号パワー比が１：１のときは、偏波
が片方だけによった場合に比較して、受光素子５または
５′に流れる電流は半分となるので、この場合でもＯＲ
回路６１を駆動できるような抵抗値に設定する。ＯＲ回
路６１からの制御信号により図３に示したアルゴリズム
に従って、受光素子バイアス端子１５1 と受光素子５を
接続する経路および受光素子バイアス端子１５1 ′と受
光素子５′を接続する経路に切替られ、ローカルＬＤ１
２がＯＮとなって、コールドスタート制御が開始され
る。The setting of the potentials and the resistance values of the light receiving element bias terminals 15 2 and 15 2 ′ and the current-voltage converting elements 7 and 7 ′ are the same as in the first embodiment of the present invention, but they are separated into two orthogonal polarized waves. When the generated signal power ratio is 1: 1, the current flowing through the light receiving element 5 or 5 ′ becomes half as compared with the case where the polarization is due to only one side.
The resistance value is set so that the circuit 61 can be driven. According to the algorithm shown in FIG. 3, the control signal from the OR circuit 61 is switched to a path connecting the light receiving element bias terminal 15 1 and the light receiving element 5 and a path connecting the light receiving element bias terminal 15 1 ′ and the light receiving element 5 ′. , Local LD1
2 is turned on and cold start control is started.
【００２７】図５に示すように、コールドスタート制御
回路１１′では、コールドスタート制御部２３は、信号
光検出信号を受けてＬＤバイアス電流および温度を初期
値に設定した後に、二つの主信号分岐１０および１０′
からのＩＦ信号をそれぞれのパワー検出部６５および６
５′で検出し、比較部６７で大きい方を切替スイッチ６
８により選択する。選択されたＩＦ信号を周波数弁別部
２１で弁別し、ＩＦ信号が検出されない場合は、切替ス
イッチ４″をコールドスタート制御部２３の側とし、Ｌ
Ｄバイアス電流可変部２５およびＬＤ温度可変部２６を
制御する。周波数弁別部２１よりＩＦ信号が検出された
場合は、切替スイッチ４″をＡＦＣ制御部２４の側と
し、ＬＤバイアス電流可変部２５を制御してＡＦＣ動作
を行う。また、切替スイッチ４および４′、電流電圧変
換素子７および７′、受光素子バイアス端子１５2 およ
び１５2 ′をそれぞれ受光素子５および５′の側に設け
たが、それぞれ受光素子６および６′の側に設けても同
様である。As shown in FIG. 5, in the cold start control circuit 11 ', the cold start control unit 23 receives the signal light detection signal and sets the LD bias current and the temperature to the initial values, and then the two main signal branches. 10 and 10 '
The IF signals from the respective power detection units 65 and 6
5 ', and the comparison unit 67 selects the larger one by the changeover switch 6
Select by 8. The selected IF signal is discriminated by the frequency discriminating unit 21, and when the IF signal is not detected, the changeover switch 4 ″ is set to the cold start control unit 23 side and L
The D bias current varying unit 25 and the LD temperature varying unit 26 are controlled. When the IF signal is detected by the frequency discriminating unit 21, the changeover switch 4 ″ is set to the AFC control unit 24 side to control the LD bias current changing unit 25 to perform the AFC operation. Further, the changeover switches 4 and 4 ′. , the current-voltage conversion element 7 and 7 'are provided on the side of each light-receiving element 6 and 6'', the light receiving element bias terminal 15 2 and 15 2' each light-receiving element 5 and 5 similarly be provided on the side of is there.
【００２８】本発明第二実施例は、偏波ダイバーシティ
形コヒーレント光受信方式として説明したが、光ホモダ
イン受信方式についても同様に実施できる。The second embodiment of the present invention has been described as the polarization diversity type coherent optical receiving system, but the optical homodyne receiving system can be similarly implemented.
【００２９】本発明第一および第二実施例では、電流電
圧変換素子７には抵抗を用いたが、トランジスタや演算
増幅器を用いる構成とすることもできる。In the first and second embodiments of the present invention, the current-voltage converting element 7 uses a resistor, but a transistor or an operational amplifier may be used.
【００３０】[0030]
【発明の効果】以上説明したように、本発明によれば、
コールドスタート制御における信号光の検出を受信感度
の劣化や装置規模を増大させることのない簡易な回路で
実現できる。As described above, according to the present invention,
The detection of the signal light in the cold start control can be realized by a simple circuit that does not deteriorate the receiving sensitivity or increase the device scale.
【図１】本発明第一実施例の全体構成図。FIG. 1 is an overall configuration diagram of a first embodiment of the present invention.
【図２】本発明第一実施例装置の構成図。FIG. 2 is a configuration diagram of a first embodiment device of the present invention.
【図３】本発明第一実施例の動作を示すフローチャー
ト。FIG. 3 is a flowchart showing the operation of the first embodiment of the present invention.
【図４】本発明第二実施例の全体構成図。FIG. 4 is an overall configuration diagram of a second embodiment of the present invention.
【図５】本発明第二実施例装置の構成図。FIG. 5 is a configuration diagram of a second embodiment device of the present invention.
【図６】従来例の動作を示すフローチャート。FIG. 6 is a flowchart showing the operation of a conventional example.
１ 光入力端子 ２ 偏波制御器 ３ 光フロントエンド回路 ４、４′、４″、６８ 切替スイッチ ５、５′、６、６′受光素子 ７、７′電流電圧変換素子 ８、８′受光素子用負荷抵抗 ９、９′プリアンプ １０、１０′主信号分岐 １１、１１′コールドスタート制御回路 １２ ローカルＬＤ １３、１３′復調回路 １４ 出力端子 １５1 〜１５3 、１５1 ′〜１５3 ′受光素子バイアス
端子 １６、１６′ 端子 １７ バイアス電流供給回路 １９ 識別回路 ２０ タイミング抽出回路 ２１ 周波数弁別部 ２３ コールドスタート制御部 ２４ ＡＦＣ制御部 ２５ ＬＤバイアス電流可変部 ２６ ＬＤ温度可変部 ２７ ＬＤ電源回路 ５１ 偏波ダイバーシティ光フロントエンド回路 ６１ ＯＲ回路 ６４ 合成回路 ６５、６５′パワー検出部 ６７ 比較部1 Optical Input Terminal 2 Polarization Controller 3 Optical Front End Circuit 4, 4 ', 4 ", 68 Changeover Switch 5, 5', 6, 6'Light-Receiving Element 7, 7'Current-Voltage Conversion Element 8, 8'-Light-Receiving Element use a load resistor 9, 9 'preamplifier 10, 10' main signal branch 11, 11 'cold start control circuit 12 local LD 13, 13' demodulating circuit 14 output terminal 15 1 to 15 3, 15 1 '15 3' receiving element Bias terminal 16, 16 'terminal 17 Bias current supply circuit 19 Discrimination circuit 20 Timing extraction circuit 21 Frequency discrimination unit 23 Cold start control unit 24 AFC control unit 25 LD bias current variable unit 26 LD temperature variable unit 27 LD power supply circuit 51 Polarized wave Diversity optical front end circuit 61 OR circuit 64 Combining circuit 65, 65 'Power detection unit 67 Comparison unit
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.5 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｈ０４Ｂ 10/06 ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 5 Identification code Office reference number FI technical display location H04B 10/06
Claims (2)
と、このローカル光源の電源回路と、このコヒーレント
光と受信信号光を混合する手段と、この手段の出力光を
電気信号に変換する受光素子と、この受光素子を動作状
態にバイアスするバイアス電流供給回路とを備えた光信
号受信機において、 前記電源回路には、受信待機状態で前記ローカル光源を
滅灯状態に制御する制御回路が接続され、 この制御回路は、前記バイアス電流供給回路の出力電流
が所定値を越えたときに自動的に前記ローカル光源を点
灯させる制御手段を含むことを特徴とする光信号受信
機。1. A local light source for generating coherent light, a power supply circuit for the local light source, a means for mixing the coherent light and the received signal light, and a light receiving element for converting the output light of the means into an electric signal. In an optical signal receiver provided with a bias current supply circuit for biasing the light receiving element to an operating state, the power supply circuit is connected to a control circuit for controlling the local light source to be extinguished in a reception standby state, The optical signal receiver, wherein the control circuit includes control means for automatically turning on the local light source when the output current of the bias current supply circuit exceeds a predetermined value.
光の中間周波信号が含まれていることを検出する手段
と、 この手段の検出出力がないときに前記電源回路を制御し
て前記ローカル光源を滅灯させる制御手段とを備えた請
求項１記載の光信号受信機。2. A means for detecting that the output electric signal of the light receiving element includes an intermediate frequency signal of received signal light, and controlling the power supply circuit when there is no detection output of this means to control the local power. The optical signal receiver according to claim 1, further comprising control means for turning off the light source.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4135208A JP2726889B2 (en) | 1992-05-27 | 1992-05-27 | Optical signal receiver |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4135208A JP2726889B2 (en) | 1992-05-27 | 1992-05-27 | Optical signal receiver |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05327616A true JPH05327616A (en) | 1993-12-10 |
| JP2726889B2 JP2726889B2 (en) | 1998-03-11 |
Family
ID=15146384
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4135208A Expired - Fee Related JP2726889B2 (en) | 1992-05-27 | 1992-05-27 | Optical signal receiver |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2726889B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010109847A (en) * | 2008-10-31 | 2010-05-13 | Fujitsu Ltd | Optical receiver for controlling wavelength of local oscillation light and local oscillation light control method |
| JP2012147255A (en) * | 2011-01-12 | 2012-08-02 | Sharp Corp | Sensor device and electronic apparatus |
| WO2015029091A1 (en) * | 2013-08-30 | 2015-03-05 | 日本電気株式会社 | Optical transmission apparatus, optical reception apparatus, optical communication apparatus, optical communication system, and methods for controlling optical transmission apparatus, optical reception apparatus, optical communication apparatus, and optical communication system |
| JP2019213212A (en) * | 2018-01-16 | 2019-12-12 | 日本電気株式会社 | Optical transmitting device, optical receiving device, optical communication device, optical communication system, and method of controlling them |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05276114A (en) * | 1992-03-26 | 1993-10-22 | Fujitsu Ltd | Receiver for coherent optical wave communication and called start method |
-
1992
- 1992-05-27 JP JP4135208A patent/JP2726889B2/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH05276114A (en) * | 1992-03-26 | 1993-10-22 | Fujitsu Ltd | Receiver for coherent optical wave communication and called start method |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010109847A (en) * | 2008-10-31 | 2010-05-13 | Fujitsu Ltd | Optical receiver for controlling wavelength of local oscillation light and local oscillation light control method |
| JP2012147255A (en) * | 2011-01-12 | 2012-08-02 | Sharp Corp | Sensor device and electronic apparatus |
| US8681192B2 (en) | 2011-01-12 | 2014-03-25 | Sharp Kabushiki Kaisha | Sensor device and electronic apparatus |
| WO2015029091A1 (en) * | 2013-08-30 | 2015-03-05 | 日本電気株式会社 | Optical transmission apparatus, optical reception apparatus, optical communication apparatus, optical communication system, and methods for controlling optical transmission apparatus, optical reception apparatus, optical communication apparatus, and optical communication system |
| JPWO2015029091A1 (en) * | 2013-08-30 | 2017-03-02 | 日本電気株式会社 | Optical transmitter, optical receiver, optical communication device, optical communication system, and control methods thereof |
| US10855377B2 (en) | 2013-08-30 | 2020-12-01 | Nec Corporation | Optical transmission apparatus, optical reception apparatus, optical communication apparatus, optical communication system, and methods of controlling them |
| US11296793B2 (en) | 2013-08-30 | 2022-04-05 | Nec Corporation | Optical transmission apparatus, optical reception apparatus, optical communications apparatus, optical communication system, and methods of controlling them |
| US11637633B2 (en) | 2013-08-30 | 2023-04-25 | Nec Corporation | Optical transmission apparatus, optical reception apparatus, optical communications apparatus, optical communication system, and methods of controlling them |
| US11936431B2 (en) | 2013-08-30 | 2024-03-19 | Nec Corporation | Optical transmission apparatus, optical reception apparatus, optical communication apparatus, optical communication system, and methods of controlling them |
| JP2019213212A (en) * | 2018-01-16 | 2019-12-12 | 日本電気株式会社 | Optical transmitting device, optical receiving device, optical communication device, optical communication system, and method of controlling them |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2726889B2 (en) | 1998-03-11 |
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