JPH09214428A - Wavelength monitor method and optical amplifier using the same - Google Patents
Wavelength monitor method and optical amplifier using the sameInfo
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- JPH09214428A JPH09214428A JP8017501A JP1750196A JPH09214428A JP H09214428 A JPH09214428 A JP H09214428A JP 8017501 A JP8017501 A JP 8017501A JP 1750196 A JP1750196 A JP 1750196A JP H09214428 A JPH09214428 A JP H09214428A
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- signal
- power
- multiplexed
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、波長多重光伝送シ
ステムにおいて伝送される波長多重光信号の波長多重数
を検出する波長監視方法、および波長多重光信号を増幅
する光増幅装置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wavelength monitoring method for detecting the wavelength multiplex number of wavelength multiplexed optical signals transmitted in a wavelength multiplexed optical transmission system, and an optical amplifier for amplifying wavelength multiplexed optical signals.
【０００２】[0002]
【従来の技術】波長多重光伝送システムでは、システム
の信頼性および伝送品質を確保するために、中継器また
は受信装置における波長多重数の監視は重要な課題であ
る。また、波長多重光信号を光のままで分岐／挿入を行
う将来の技術においても、各ノードで伝送されている波
長多重数を知ることは重要である。しかし、現在、波長
多重光信号の波長多重数を簡便に検出する方法はない。2. Description of the Related Art In a wavelength division multiplexing optical transmission system, it is an important issue to monitor the number of wavelength division multiplexing in a repeater or a receiver in order to secure system reliability and transmission quality. Further, even in the future technology of dropping / adding a wavelength-multiplexed optical signal as light, it is important to know the number of wavelength-multiplexed signals transmitted at each node. However, at present, there is no simple method for detecting the wavelength division number of the wavelength division multiplexed optical signal.
【０００３】[0003]
【発明が解決しようとする課題】波長多重光伝送システ
ムでは、波長多重されるチャネルの一部がレーザ光源の
劣化等により光出力が所要値より低下して伝送不能とな
ることがある。このような場合に、光中継器でその出力
パワーを一定に保つ制御を行うと、波長多重数（チャネ
ル数）が減るごとに１波長あたりの信号光パワーが増加
する。各波長の信号光パワーが増加すると、伝送路であ
る光ファイバの非線形効果により伝送特性の劣化が大き
くなる。In the wavelength-division multiplexed optical transmission system, the optical output of a part of the wavelength-division-multiplexed channels may become lower than the required value due to deterioration of the laser light source and the transmission may be impossible. In such a case, if control is performed to keep the output power constant in the optical repeater, the signal light power per wavelength increases as the wavelength multiplexing number (channel number) decreases. When the signal light power of each wavelength increases, the deterioration of the transmission characteristics increases due to the nonlinear effect of the optical fiber that is the transmission line.
【０００４】また、受信装置は、波長多重光信号を光増
幅した後に各波長成分に分波し、各波長ごとに受光素子
に受光させる構成になっている。この場合にも同様に、
波長多重数が減るごとに１波長あたりの信号光パワーが
増加する。その結果、各波長対応の受光素子に入射する
パワーが増加し、受信装置の故障の原因となることがあ
る。Further, the receiving device is constructed such that the wavelength-multiplexed optical signal is optically amplified and then demultiplexed into each wavelength component, and the light receiving element receives each wavelength. In this case as well,
The signal light power per wavelength increases as the number of wavelength division multiplexing decreases. As a result, the power incident on the light receiving element corresponding to each wavelength increases, which may cause a failure of the receiving device.
【０００５】したがって、波長多重光伝送システムで
は、波長多重光信号のトータルパワーを一定に保つので
はなく、各波長ごとの信号光パワーが一定になるように
制御することが必要になる。今伝送されている波長多重
数を検出し、波長多重光信号の増幅処理にフィードバッ
クすることにより、その正確な制御が可能となる。本発
明は、波長多重光信号の波長多重数を検出する波長監視
方法、および検出された波長多重数に基づいて各波長の
信号光パワーが一定になるように制御する光増幅装置を
提供することを目的とする。Therefore, in the wavelength division multiplexing optical transmission system, it is necessary to control so that the signal light power for each wavelength becomes constant, instead of keeping the total power of the wavelength division multiplexing optical signal constant. By detecting the number of wavelength-multiplexed signals that are being transmitted and feeding them back to the amplification process of the wavelength-multiplexed optical signal, it is possible to control them accurately. The present invention provides a wavelength monitoring method for detecting the wavelength multiplexing number of a wavelength multiplexed optical signal, and an optical amplifier device for controlling the signal light power of each wavelength to be constant based on the detected wavelength multiplexing number. With the goal.
【０００６】[0006]
【課題を解決するための手段】ディジタル光伝送システ
ムでは、外部強度変調器を用いて強度変調された光信号
が伝送される。電気光学結晶（ＬiＮbＯ3)を用いた強度
変調器の駆動電圧と光出力の関係を図１に示す。強度変
調器は、駆動電圧に対して光出力が正弦波状に変化す
る。そこで、図１(a) に示すように、光出力が０となる
点にＤＣバイアスを加え、ここを動作点としてデータ信
号を加えることによりデータ信号と同様の光出力が得ら
れる。一方、図１(b) に示すように、光出力が０となる
最適点からＤＣバイアスがずれた場合には、光出力の波
形に歪みが生ずる。In a digital optical transmission system, an intensity modulated optical signal is transmitted using an external intensity modulator. FIG. 1 shows the relationship between the drive voltage and the light output of the intensity modulator using the electro-optic crystal (LiNbO 3 ). In the intensity modulator, the optical output changes sinusoidally with respect to the driving voltage. Therefore, as shown in FIG. 1 (a), a DC bias is applied to the point where the optical output becomes 0, and a data signal is added with this point as the operating point to obtain an optical output similar to that of the data signal. On the other hand, as shown in FIG. 1B, when the DC bias deviates from the optimum point where the optical output becomes 0, the waveform of the optical output is distorted.
【０００７】強度変調器は、時間とともに強度変調に最
適なＤＣバイアスの値が変動する問題点がある。このＤ
Ｃドリフトを解決するためにデータ信号の０または１に
低周波の正弦波を重畳し、強度変調器の出力光からその
低周波成分を検出し、その位相に応じてＤＣバイアスを
制御する方法が提案されている（桑田 他、1990年電子
情報通信学会春季全国大会、論文番号Ｂ-976）。以下、
図２〜４を参照して本方法について説明する。The intensity modulator has a problem that the value of the DC bias optimum for intensity modulation varies with time. This D
In order to solve the C drift, a method of superimposing a low frequency sine wave on 0 or 1 of the data signal, detecting the low frequency component from the output light of the intensity modulator, and controlling the DC bias according to the phase is a method. Proposed (Kuwata et al., 1990 IEICE Spring National Convention, paper number B-976). Less than,
This method will be described with reference to FIGS.
【０００８】図２は、ＤＣバイアス制御に用いる低周波
信号とデータ信号および光出力の関係を示す。図３(a)
は動作点が低電圧側にずれた場合の低周波信号に対する
光出力を示し、図３(b) は動作点が高電圧側にずれた場
合の低周波信号に対する光出力を示す。この方法の重要
なポイントは、(1) データ信号の０と１に重畳する低周
波信号の位相が反転している点、(2) (1) により、光出
力の０と１における低周波成分の位相が同一になる点、
(3) 図３(a),(b) に示すように、動作点が低電圧側にず
れた場合と高電圧側にずれた場合とで、光出力の低周波
成分の位相が反転する点である。FIG. 2 shows the relationship among a low frequency signal used for DC bias control, a data signal and an optical output. Fig. 3 (a)
Shows the optical output for the low-frequency signal when the operating point shifts to the low voltage side, and FIG. 3B shows the optical output for the low-frequency signal when the operating point shifts to the high voltage side. The important point of this method is that (1) the phase of the low frequency signal superimposed on 0 and 1 of the data signal is inverted, and (2) (1), the low frequency components at 0 and 1 of the optical output are Points of the same phase,
(3) As shown in FIGS. 3 (a) and 3 (b), the point where the phase of the low-frequency component of the optical output is inverted depending on whether the operating point is shifted to the low voltage side or the high voltage side. Is.
【０００９】したがって、この強度変調器の光出力を受
光素子で電気信号に変換した場合には、重畳されている
低周波成分の位相をみることにより動作点がどちらの方
向にずれているかを知ることができる。すなわち、受光
素子から出力される電気信号の低周波成分の位相と、デ
ータ信号に加えられた低周波成分の位相を位相比較器で
比較し、その出力をＤＣバイアスにフィードバックする
ことにより、最適な方向への動作点制御が可能となる。
図４は、最適な動作点における低周波信号に対する光出
力を示す。ここに示すように、動作点が最適なバイアス
点にある場合には、データ信号に重畳した低周波信号の
２倍の周波数成分が光出力に生ずる。ただし、光出力の
０と１で低周波信号の位相が反転する。Therefore, when the light output of the intensity modulator is converted into an electric signal by the light receiving element, it is possible to know in which direction the operating point deviates by observing the phase of the superimposed low frequency component. be able to. That is, the phase of the low frequency component of the electric signal output from the light receiving element and the phase of the low frequency component added to the data signal are compared by the phase comparator, and the output is fed back to the DC bias to obtain the optimum value. It is possible to control the operating point in the direction.
FIG. 4 shows the optical output for low frequency signals at the optimum operating point. As shown here, when the operating point is at the optimum bias point, a frequency component twice as high as the low frequency signal superimposed on the data signal is generated in the optical output. However, the phase of the low frequency signal is inverted at 0 and 1 of the optical output.
【００１０】また、図５に示すように、データ信号の１
（または０）のみに低周波信号を重畳してもＤＣドリフ
トの制御を行うことができる。図６(a) は動作点が低電
圧側にずれた場合の低周波信号に対する光出力を示し、
図６(b) は動作点が高電圧側にずれた場合の低周波信号
に対する光出力を示す。図７は、最適な動作点における
低周波信号に対する光出力を示す。ここに示すように、
動作点が最適なバイアス点にある場合には、データ信号
に重畳した低周波信号の２倍の周波数成分が光出力に生
ずる。ただし、データ信号が１（または０）の場合にの
み低周波信号を重畳しているので、光出力の０と１とで
低周波信号の位相が反転することはない。In addition, as shown in FIG.
The DC drift can be controlled even if the low frequency signal is superimposed only on (or 0). Figure 6 (a) shows the optical output for low frequency signals when the operating point is shifted to the low voltage side.
FIG. 6B shows the optical output for a low frequency signal when the operating point is shifted to the high voltage side. FIG. 7 shows the optical output for low frequency signals at the optimum operating point. As shown here,
When the operating point is at the optimum bias point, a frequency component twice as high as the low frequency signal superimposed on the data signal is generated in the optical output. However, since the low frequency signal is superimposed only when the data signal is 1 (or 0), the phase of the low frequency signal is not inverted between 0 and 1 of the optical output.
【００１１】本発明の波長監視方法は、このＤＣバイア
ス制御用に重畳される低周波信号を利用するものであ
り、波長多重光信号の各波長ごとに重畳する周波数を変
え、受光後の電気領域で各周波数成分をモニタする。こ
れにより、波長多重光信号の波長多重数（チャネル数）
および波長（チャネル番号）を検出することができる。
本発明の光増幅装置は、検出された波長多重数に基づい
て波長多重光信号を増幅する光増幅部の利得を制御する
構成である。光増幅部として半導体レーザ増幅器を用い
た場合には、バイアス電流の制御により利得の制御が可
能である。光増幅部として光ファイバ増幅器を用いた場
合には、励起光パワーを制御することにより利得の制御
が可能である。なお、励起光パワーの制御は、励起光源
として半導体レーザを用いた場合にはそのバイアス電流
の制御によって行う。The wavelength monitoring method of the present invention utilizes the low-frequency signal superimposed for the DC bias control. The frequency to be superimposed is changed for each wavelength of the wavelength-multiplexed optical signal, and the electrical region after receiving light is changed. Monitor each frequency component with. As a result, the number of multiplexed wavelengths (number of channels) of the wavelength multiplexed optical signal
And the wavelength (channel number) can be detected.
The optical amplifying device of the present invention is configured to control the gain of the optical amplifying unit that amplifies the WDM optical signal based on the detected WDM number. When a semiconductor laser amplifier is used as the optical amplifier, the gain can be controlled by controlling the bias current. When an optical fiber amplifier is used as the optical amplifier, the gain can be controlled by controlling the pumping light power. The pumping light power is controlled by controlling the bias current when a semiconductor laser is used as the pumping light source.
【００１２】[0012]
（第１の実施形態）図８は、本発明の波長監視方法を用
いた光増幅装置の第１の実施形態を示す。なお、本実施
形態は、図２〜４を参照して説明した原理に適用したも
のである。図において、光増幅部１には波長多重光信号
が入力され、その設定利得に応じて増幅される。送信側
では、波長多重光信号の各波長ごとに異なる周波数の低
周波信号が、データ信号の１と０に逆位相で重畳されて
いるものとする。(First Embodiment) FIG. 8 shows a first embodiment of an optical amplifier using the wavelength monitoring method of the present invention. The present embodiment is applied to the principle described with reference to FIGS. In the figure, the wavelength-multiplexed optical signal is input to the optical amplifier 1 and is amplified according to the set gain. On the transmitting side, it is assumed that low-frequency signals having different frequencies for each wavelength of the wavelength-multiplexed optical signal are superimposed on the data signals 1 and 0 in opposite phases.
【００１３】光増幅部１の出力光パワーの一部は光分岐
器２で分岐され、受光素子１１で電気信号に変換され
る。この電気信号のスペクトルを図８(b) に示す。送信
側の強度変調器の動作点が正常に制御されている場合に
は、電気信号には各波長ごとに異なる周波数で重畳され
た低周波信号の２倍の周波数成分がある。しかし、図４
に示すように、光出力の０と１で低周波信号の位相が反
転するので、その低周波信号の２倍の周波数成分の平均
電力は０となる。電気信号を入力する２乗回路１２は、
その符号依存性をなくすためのものである。したがっ
て、２乗回路１２の出力には、波長ごとに異なる周波数
をもつ信号の４倍の周波数信号が生ずる。A part of the output light power of the optical amplifier 1 is branched by the optical branching device 2 and converted into an electric signal by the light receiving element 11. The spectrum of this electric signal is shown in Fig. 8 (b). When the operating point of the intensity modulator on the transmitting side is normally controlled, the electric signal has twice the frequency component of the low frequency signal superimposed at different frequencies for each wavelength. However, FIG.
As shown in, the phase of the low-frequency signal is inverted between 0 and 1 of the optical output, so that the average power of the frequency component twice as high as that of the low-frequency signal becomes 0. The squaring circuit 12 that inputs an electric signal,
This is for eliminating the code dependence. Therefore, at the output of the squaring circuit 12, a frequency signal four times as high as a signal having a frequency different for each wavelength is generated.
【００１４】この４倍の周波数信号は、分岐回路１３で
波長多重数ｎに分割され、各波長対応の低周波信号の４
倍の周波数成分のうち、それぞれ１つのみを通過させる
帯域通過フィルタ（ＢＰＦ）１４−１〜１４−ｎに入力
される。各波長対応の所定の周波数成分は、各帯域通過
フィルタからそれぞれ対応する電力検波回路１５−１〜
１５−ｎに入力され、各周波数成分のパワーが検出され
る。各電力検波回路の出力をモニタする制御回路１６
は、各電力検波回路の出力パワーの値に応じて今伝送さ
れている波長（チャネル）を割り出し、波長多重数とそ
れぞれの光信号パワーを検出する。This frequency signal of 4 times is divided by the branching circuit 13 into the wavelength multiplex number n, and 4 of low frequency signals corresponding to respective wavelengths are obtained.
It is input to the band pass filters (BPF) 14-1 to 14-n that pass only one of the doubled frequency components. The predetermined frequency components corresponding to the respective wavelengths are transmitted from the respective band pass filters to the corresponding power detection circuits 15-1 to 15-1.
15-n, and the power of each frequency component is detected. Control circuit 16 for monitoring the output of each power detection circuit
Determines the wavelength (channel) currently being transmitted according to the value of the output power of each power detection circuit, and detects the wavelength multiplexing number and each optical signal power.
【００１５】制御回路１６は、全チャネルが正常に伝送
されているときの波長多重数およびそれぞれの光信号パ
ワーに対する値をメモリに蓄積しており、これと実際に
伝送されている波長多重数とそれぞれの光信号パワーに
基づいて光増幅部１の利得を制御し、各波長の信号光パ
ワーが一定になるように制御する。たとえば、１波長が
ダウンしている場合には、その分だけ差し引いて波長多
重光信号を増幅し、各波長の信号光パワーが必要以上に
大きくならないように制御する。The control circuit 16 stores in the memory the number of wavelengths multiplexed when all the channels are normally transmitted and the value for each optical signal power, and this and the number of wavelengths actually transmitted. The gain of the optical amplifier 1 is controlled based on the respective optical signal powers, and the signal light powers of the respective wavelengths are controlled to be constant. For example, when one wavelength is down, the wavelength-multiplexed optical signal is amplified by subtracting that amount, and control is performed so that the signal light power of each wavelength does not increase more than necessary.
【００１６】（第２の実施形態）図９は、本発明の波長
監視方法を用いた光増幅装置の第２の実施形態を示す。
なお、本実施形態は、図５〜７を参照して説明した原理
を適用したものである。図において、光増幅部１には波
長多重光信号が入力され、その設定利得に応じて増幅さ
れる。送信側では、波長多重光信号の各波長ごとに異な
る周波数の低周波信号がデータ信号の１（または０）の
みに重畳されているものとする。(Second Embodiment) FIG. 9 shows a second embodiment of an optical amplifier using the wavelength monitoring method of the present invention.
In addition, this embodiment applies the principle described with reference to FIGS. In the figure, the wavelength-multiplexed optical signal is input to the optical amplifier 1 and is amplified according to the set gain. On the transmission side, it is assumed that a low frequency signal having a different frequency for each wavelength of the wavelength division multiplexed optical signal is superimposed only on 1 (or 0) of the data signal.
【００１７】光増幅部１の出力光パワーの一部は光分岐
器２で分岐され、受光素子１１で電気信号に変換され
る。この電気信号のスペクトルを図９(b) に示す。送信
側の強度変調器の動作点が正常に制御されている場合に
は、電気信号には各波長ごとに異なる周波数で重畳され
た低周波信号の２倍の周波数成分がある。この低周波信
号の２倍の周波数成分は、分割回路１３で波長多重数ｎ
に分割され、帯域通過フィルタ（ＢＰＦ）１７−１〜１
７−ｎに入力される。各波長対応の低周波信号の２倍の
周波数成分は、各帯域通過フィルタからそれぞれ対応す
る電力検波回路１５−１〜１５−ｎに入力され、各周波
数成分のパワーが検出される。各電力検波回路の出力を
モニタする制御回路１６は、各電力検波回路の出力パワ
ーの値に応じて今伝送されている波長（チャネル）を割
り出し、波長多重数および光信号パワーを検出する。制
御回路１６は、同様にして光増幅部１の利得を制御し、
各波長の信号光パワーが一定になるように制御する。A part of the output optical power of the optical amplifier 1 is branched by the optical branching device 2 and converted into an electric signal by the light receiving element 11. The spectrum of this electric signal is shown in Fig. 9 (b). When the operating point of the intensity modulator on the transmitting side is normally controlled, the electric signal has twice the frequency component of the low frequency signal superimposed at different frequencies for each wavelength. The frequency component twice as high as this low-frequency signal is transmitted by the division circuit 13 to the wavelength multiplexing number n.
Is divided into bandpass filters (BPF) 17-1 to 17-1.
7-n. Double frequency components of the low frequency signal corresponding to each wavelength are input from the respective bandpass filters to the corresponding power detection circuits 15-1 to 15-n, and the power of each frequency component is detected. The control circuit 16 that monitors the output of each power detection circuit determines the wavelength (channel) that is currently being transmitted according to the value of the output power of each power detection circuit, and detects the wavelength multiplexing number and the optical signal power. The control circuit 16 similarly controls the gain of the optical amplification unit 1,
The signal light power of each wavelength is controlled to be constant.
【００１８】なお、第２の実施形態における波長多重光
信号については、第１の実施形態の２乗回路１２を用い
た構成でも各波長の波長監視を行うことができる。ま
た、第１の実施形態および第２の実施形態において、光
増幅部１の前段で入力光の一部を分岐する構成として
も、同様に波長監視を行い光増幅部１の利得制御を行う
ことができる。その構成例を図１０(a),(b) に示す。With respect to the wavelength-division multiplexed optical signal in the second embodiment, it is possible to monitor the wavelength of each wavelength even with the configuration using the squaring circuit 12 of the first embodiment. In addition, in the first and second embodiments, even if the configuration is such that a part of the input light is branched in the preceding stage of the optical amplification section 1, wavelength monitoring is similarly performed and the gain control of the optical amplification section 1 is performed. You can An example of the configuration is shown in FIGS. 10 (a) and 10 (b).
【００１９】また、波長多重光信号を受信する受信装置
では、図１１に示すように、前置光増幅部２１で波長多
重光信号を一括して光増幅した後に、光分波器２２で各
波長成分に分波し、さらに後置光増幅部２３−１〜２３
−ｎで各波長ごとに増幅し、受光素子２４−１〜２４−
ｎで電気信号に変換して復調回路２５−１〜２５−ｎで
処理する構成になっている。本発明の光増幅装置は、こ
のような受信装置において前置光増幅部２１の利得を制
御する構成にも適用することができる。Further, in the receiving apparatus for receiving the wavelength division multiplexed optical signal, as shown in FIG. 11, after the wavelength division multiplexed optical signal is collectively amplified by the pre-amplifier 21, the optical demultiplexer 22 is used. Wavelength components are demultiplexed, and further post-amplifiers 23-1 to 23-23
Amplify each wavelength by -n, and receive the light receiving elements 24-1 to 24-
The signal is converted into an electric signal by n and processed by the demodulation circuits 25-1 to 25-n. The optical amplification device of the present invention can also be applied to a configuration for controlling the gain of the pre-optical amplification unit 21 in such a reception device.
【００２０】[0020]
【発明の効果】以上説明したように、本発明の波長監視
方法では、複数のチャネルが波長多重された波長多重光
信号の一部のチャネルが伝送されなくなっても、受信側
で容易のそのチャネルを識別でき、かつ波長多重数を検
出することができる。この波長多重数に応じて光増幅部
の利得を制御する光増幅装置では、各波長の信号光パワ
ーが一定になるように制御することができる。As described above, according to the wavelength monitoring method of the present invention, even if some channels of the wavelength-multiplexed optical signal in which a plurality of channels are wavelength-multiplexed are not transmitted, the channels can be easily received by the receiving side. Can be identified, and the number of wavelength multiplexes can be detected. In the optical amplifying device that controls the gain of the optical amplifying unit according to the number of wavelength division multiplexing, the signal light power of each wavelength can be controlled to be constant.
【図１】強度変調器の駆動電圧と光出力の関係を示す
図。FIG. 1 is a diagram showing a relationship between a drive voltage of an intensity modulator and an optical output.
【図２】ＤＣバイアス制御に用いる低周波信号とデータ
信号および光出力の関係を示す図。FIG. 2 is a diagram showing a relationship among a low-frequency signal used for DC bias control, a data signal, and an optical output.
【図３】動作点がずれているときの低周波信号に対する
光出力を示す図。FIG. 3 is a diagram showing an optical output with respect to a low-frequency signal when the operating point is deviated.
【図４】最適な動作点における低周波信号に対する光出
力を示す図。FIG. 4 is a diagram showing an optical output with respect to a low frequency signal at an optimum operating point.
【図５】ＤＣバイアス制御に用いる低周波信号とデータ
信号および光出力の関係を示す図。FIG. 5 is a diagram showing a relationship among a low frequency signal used for DC bias control, a data signal, and an optical output.
【図６】動作点がずれているときの低周波信号に対する
光出力を示す図。FIG. 6 is a diagram showing an optical output with respect to a low-frequency signal when the operating point is deviated.
【図７】最適な動作点における低周波信号に対する光出
力を示す図。FIG. 7 is a diagram showing an optical output with respect to a low frequency signal at an optimum operating point.
【図８】本発明の波長監視方法を用いた光増幅装置の第
１の実施形態を示す図。FIG. 8 is a diagram showing a first embodiment of an optical amplifier using the wavelength monitoring method of the present invention.
【図９】本発明の波長監視方法を用いた光増幅装置の第
２の実施形態を示す図。FIG. 9 is a diagram showing a second embodiment of an optical amplifier using the wavelength monitoring method of the present invention.
【図１０】本発明の波長監視方法を用いた光増幅装置の
他の実施形態を示す図。FIG. 10 is a diagram showing another embodiment of an optical amplifier using the wavelength monitoring method of the present invention.
【図１１】本発明の光増幅装置を受信装置に適用した実
施形態を示す図。FIG. 11 is a diagram showing an embodiment in which the optical amplifying device of the present invention is applied to a receiving device.
１ 光増幅部 ２ 光分岐器 １１ 受光素子 １２ ２乗回路 １３ 分岐回路 １４，１７ 帯域通過フィルタ（ＢＰＦ） １５ 電力検波回路 １６ 制御回路 ２１ 前置光増幅部 ２２ 光分波器 ２３ 後置光増幅部 ２４ 受光素子 ２５ 復調回路 DESCRIPTION OF SYMBOLS 1 Optical amplification part 2 Optical branching device 11 Light receiving element 12 Square circuit 13 Branching circuit 14, 17 Band pass filter (BPF) 15 Power detection circuit 16 Control circuit 21 Pre-optical amplification part 22 Optical demultiplexer 23 Post-optical amplification 23 Part 24 Light receiving element 25 Demodulation circuit
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.6 識別記号 庁内整理番号 ＦＩ 技術表示箇所 Ｈ０４Ｂ 10/14 10/06 10/04 ─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. 6 Identification code Internal reference number FI technical display location H04B 10/14 10/06 10/04
Claims (4)
とに異なる周波数の低周波信号が重畳されたデータ信号
により変調されており、 前記波長多重光信号から前記低周波信号の２倍の周波数
それぞれに対応した周波数成分の電力を検出し、各周波
数成分の電力に応じて波長多重されている波長および波
長多重数を検出することを特徴とする波長監視方法。1. The light of each wavelength of the wavelength-multiplexed optical signal is modulated by a data signal on which a low-frequency signal having a different frequency for each wavelength is superimposed. The wavelength monitoring method is characterized by detecting the power of the frequency component corresponding to each of the frequencies, and detecting the wavelength and the wavelength multiplexing number that are wavelength-multiplexed according to the power of each frequency component.
とに異なる周波数の低周波信号が重畳されたデータ信号
により変調されており、 前記波長多重光信号から前記低周波信号の４倍の周波数
それぞれに対応した周波数成分の電力を検出し、各周波
数成分の電力に応じて波長多重されている波長および波
長多重数を検出することを特徴とする波長監視方法。2. The light of each wavelength of the wavelength-multiplexed optical signal is modulated by a data signal on which a low-frequency signal having a different frequency for each wavelength is superimposed. The wavelength monitoring method is characterized by detecting the power of the frequency component corresponding to each of the frequencies, and detecting the wavelength and the wavelength multiplexing number that are wavelength-multiplexed according to the power of each frequency component.
データ信号の０と１に逆位相で重畳され、そのデータ信
号により変調された光が波長多重されて入力され、その
波長多重光信号を光増幅する光増幅部を備えた光増幅装
置において、 前記光増幅部の入力部または出力部で前記波長多重光信
号の光パワーの一部を分岐する光分岐手段と、 前記光分岐器で分岐された波長多重光信号を電気信号に
変換する光電気変換手段と、 前記電気信号を２乗する２乗手段と、 前記２乗手段の出力から、前記各波長対応の低周波信号
の４倍の周波数それぞれに対応した周波数成分を選択す
る周波数選択手段と、 前記周波数選択手段で選択された各波長対応の周波数成
分の電力を検出する電力検波手段と、 前記各波長対応の周波数成分の電力に応じて波長多重さ
れている波長多重数を検出し、その波長多重数に応じて
前記光増幅部の利得を制御する制御手段とを備えたこと
を特徴とする光増幅装置。3. A low-frequency signal having a different frequency for each wavelength is superposed on 0 and 1 of a data signal in opposite phases, and the light modulated by the data signal is wavelength-multiplexed and input, and the wavelength-multiplexed optical signal is In an optical amplifying device including an optical amplifying unit for performing optical amplification, an optical branching unit for branching a part of the optical power of the wavelength multiplexed optical signal at an input unit or an output unit of the optical amplifying unit, and a branch at the optical branching unit An opto-electrical conversion means for converting the wavelength-division multiplexed optical signal into an electric signal, a squaring means for squaring the electric signal, and an output of the squaring means for quadruple the low frequency signal corresponding to each wavelength. Frequency selection means for selecting frequency components corresponding to respective frequencies, power detection means for detecting the power of the frequency components corresponding to the respective wavelengths selected by the frequency selection means, and depending on the power of the frequency components corresponding to the respective wavelengths. Many wavelengths An optical amplifying device, comprising: a control unit that detects the number of multiplexed wavelengths and controls the gain of the optical amplifier according to the number of multiplexed wavelengths.
データ信号の０または１のいずれかに重畳され、そのデ
ータ信号により変調された光が波長多重されて入力さ
れ、その波長多重光信号を光増幅する光増幅部を備えた
光増幅装置において、 前記光増幅部の入力部または出力部で前記波長多重光信
号の光パワーの一部を分岐する光分岐手段と、 前記光分岐器で分岐された波長多重光信号を電気信号に
変換する光電気変換手段と、 前記電気信号から、前記各波長対応の低周波信号の２倍
の周波数それぞれに対応した周波数成分を選択する周波
数選択手段と、 前記周波数選択手段で選択された各波長対応の周波数成
分の電力を検出する電力検波手段と、 前記各波長対応の周波数成分の電力に応じて波長多重さ
れている波長多重数を検出し、その波長多重数に応じて
前記光増幅部の利得を制御する制御手段とを備えたこと
を特徴とする光増幅装置。4. A low-frequency signal having a different frequency for each wavelength is superimposed on either 0 or 1 of a data signal, and the light modulated by the data signal is wavelength-multiplexed and input, and the wavelength-multiplexed optical signal is In an optical amplifying device including an optical amplifying unit for performing optical amplification, an optical branching unit for branching a part of the optical power of the wavelength multiplexed optical signal at an input unit or an output unit of the optical amplifying unit, and a branch at the optical branching unit Opto-electric conversion means for converting the wavelength-division multiplexed optical signal into an electrical signal, and frequency selection means for selecting from the electrical signal a frequency component corresponding to each double frequency of the low frequency signal corresponding to each wavelength. A power detection unit that detects the power of the frequency component corresponding to each wavelength selected by the frequency selection unit, and a wavelength multiplexing number that is wavelength-multiplexed according to the power of the frequency component corresponding to each wavelength. Optical amplifying apparatus being characterized in that a control means for controlling a gain of the optical amplifier unit depending on the number of multiplexed wavelengths.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8017501A JPH09214428A (en) | 1996-02-02 | 1996-02-02 | Wavelength monitor method and optical amplifier using the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP8017501A JPH09214428A (en) | 1996-02-02 | 1996-02-02 | Wavelength monitor method and optical amplifier using the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH09214428A true JPH09214428A (en) | 1997-08-15 |
Family
ID=11945748
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8017501A Pending JPH09214428A (en) | 1996-02-02 | 1996-02-02 | Wavelength monitor method and optical amplifier using the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH09214428A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5995276A (en) * | 1996-07-04 | 1999-11-30 | Nec Corporation | Wavelength-division-multiplexing optical amplifier device and wavelength-division-multiplexing optical transmission system |
| JP2003069533A (en) * | 2001-08-23 | 2003-03-07 | Oki Electric Ind Co Ltd | Device and system for optical multiplex transmission |
| US8699884B2 (en) | 2009-03-30 | 2014-04-15 | Fujitsu Limited | Optical transmission system and optical transmission method |
-
1996
- 1996-02-02 JP JP8017501A patent/JPH09214428A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5995276A (en) * | 1996-07-04 | 1999-11-30 | Nec Corporation | Wavelength-division-multiplexing optical amplifier device and wavelength-division-multiplexing optical transmission system |
| JP2003069533A (en) * | 2001-08-23 | 2003-03-07 | Oki Electric Ind Co Ltd | Device and system for optical multiplex transmission |
| US8699884B2 (en) | 2009-03-30 | 2014-04-15 | Fujitsu Limited | Optical transmission system and optical transmission method |
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