JPH0621898A - Distortion compnesation system for modulated optical signal - Google Patents
Distortion compnesation system for modulated optical signalInfo
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- JPH0621898A JPH0621898A JP4177946A JP17794692A JPH0621898A JP H0621898 A JPH0621898 A JP H0621898A JP 4177946 A JP4177946 A JP 4177946A JP 17794692 A JP17794692 A JP 17794692A JP H0621898 A JPH0621898 A JP H0621898A
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- light
- error signal
- modulated
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、光通信等に用いられる
変調光信号を発生する回路に関し、特にこのような回路
において、変調光信号の歪みを除去することができる、
変調光信号の歪み補償方式に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit for generating a modulated optical signal used in optical communication and the like, and particularly in such a circuit, distortion of the modulated optical signal can be removed.
The present invention relates to a distortion compensation method for a modulated optical signal.
【０００２】光を通信等の目的に利用する場合には、一
般に、光の強度等を入力信号に応じて変調することによ
って変調光信号として伝送し、受信側においてこれを復
調して、もとの信号を復元する方式が用いられている。In the case of utilizing light for the purpose of communication or the like, in general, the intensity of light or the like is modulated according to an input signal to be transmitted as a modulated optical signal, which is demodulated on the receiving side to obtain the original signal. The method of restoring the signal is used.
【０００３】このような、変調光を発生する回路におい
ては、光変調器が有する静特性の非直線性によって生じ
る、出力変調光信号が有する歪みを除去することができ
る、変調光信号の歪み補償方式が要望されている。In such a circuit for generating modulated light, the distortion of the output modulated optical signal, which is caused by the non-linearity of the static characteristic of the optical modulator, can be removed. A method is required.
【０００４】[0004]
【従来の技術】図３は、従来の変調光信号発生回路の原
理的構成を示したものであって、１１は主信号用光変調
器を示し、その発生光を伝送すべき主信号（電気信号）
入力によって変調することによって、変調光信号が出力
される。2. Description of the Related Art FIG. 3 shows a principle configuration of a conventional modulated optical signal generation circuit, in which 11 is an optical modulator for a main signal, and the generated optical signal (electric signal) to be transmitted. signal)
A modulated optical signal is output by modulating the input signal.
【０００５】図３の回路において、光変調器としては、
半導体レーザ（以下ＬＤという）等の発光素子や、電界
吸収型光変調器（以下ＥＡＭという）や、ＬｉＮｂＯ3
マッハツェンダ型光変調器（以下ＬＮという）等の外部
変調器が用いられる。図４，図５，図６は、それぞれＬ
Ｄ，ＥＡＭ，ＬＮの静特性を例示したものである。In the circuit of FIG. 3, the optical modulator is
A light emitting element such as a semiconductor laser (hereinafter referred to as LD), an electroabsorption type optical modulator (hereinafter referred to as EAM), LiNbO 3
An external modulator such as a Mach-Zehnder type optical modulator (hereinafter referred to as LN) is used. 4, FIG. 5, and FIG.
This is an example of static characteristics of D, EAM, and LN.
【０００６】これらの光変調器においては、例えばＬＤ
の場合は、変調入力に応じて制御電流ＩCONTを変化させ
ることによって、光出力パワーＰが変化して変調が行わ
れる。またＥＡＭやＬＮの場合は、変調入力に応じて制
御電圧ＶCONTを変化させることによって、光透過率φが
変化して変調が行われる。In these optical modulators, for example, LD
In the case of 1, the optical output power P is changed and modulation is performed by changing the control current I CONT according to the modulation input. In the case of EAM or LN, the light transmittance φ is changed by changing the control voltage V CONT according to the modulation input, and modulation is performed.
【０００７】[0007]
【発明が解決しようとする課題】従来の光変調器におい
ては、その静特性における非直線性に基づいて、変調光
出力において、歪みが生じることが避けられない。変調
光信号出力における非直線歪みは、光信号をディジタル
信号として扱う場合には、比較的その影響が少ない。し
かしながら、光信号をアナログ信号として扱う必要があ
る場合には、伝送特性を劣化させる要因となるので、好
ましくない。In the conventional optical modulator, it is unavoidable that distortion occurs in the modulated light output due to the non-linearity in the static characteristics. The nonlinear distortion in the output of the modulated optical signal has a relatively small effect when the optical signal is treated as a digital signal. However, when it is necessary to handle the optical signal as an analog signal, it becomes a factor that deteriorates the transmission characteristics, which is not preferable.
【０００８】以下においては、ＥＡＭを例にとって光変
調器における歪み発生の理由を説明する。ＥＡＭは図５
に示されるような静特性を有し、光透過率φが単調に変
化する領域において、制御電圧ＶCONTを変調することに
よって、変調光信号出力が得られる。In the following, the reason why distortion occurs in the optical modulator will be described by taking EAM as an example. Figure 5 for EAM
A modulated optical signal output can be obtained by modulating the control voltage V CONT in the region having the static characteristics as shown in (1) and the light transmittance φ monotonously changes.
【０００９】この場合、ＥＡＭの静特性の非直線性によ
って、変調光信号出力に歪みが生じる。すなわち、光透
過率φの変化領域の中心部分においては、変調効率−η
とのずれは小さく歪みの発生は無視できるが、中心部分
から離れるに従って変調効率−ηとのずれが大きくな
り、波形歪みとなって現れる。In this case, the modulated optical signal output is distorted due to the non-linearity of the static characteristics of the EAM. That is, in the central portion of the change region of the light transmittance φ, the modulation efficiency −η
However, the deviation from the modulation efficiency −η increases as the distance from the central portion increases, and the distortion appears as waveform distortion.
【００１０】図７は、矩形波変調の場合の変調波形を示
したものであって、簡単のため、変調信号を矩形波とし
たときの入出力波形を示している。図中、（ａ）は小信
号入力の場合を示し、（ｂ）は大信号入力の場合を示し
ている。FIG. 7 shows a modulation waveform in the case of rectangular wave modulation, and shows an input / output waveform when the modulation signal is a rectangular wave for simplification. In the figure, (a) shows the case of small signal input, and (b) shows the case of large signal input.
【００１１】図７（ａ）は、バイアス点を図５に示され
たφ変化領域の中心にとって、小信号で変調を行った場
合を示し、この場合は、使用領域が直線性のよい領域の
みであるため、歪みを無視することができ、入力波形と
一致した波形を有する変調出力が得られる。FIG. 7A shows a case in which the bias point is centered in the φ change region shown in FIG. 5 and modulation is performed with a small signal. In this case, the use region is only a region having good linearity. Therefore, the distortion can be ignored and a modulated output having a waveform that matches the input waveform is obtained.
【００１２】また、図７（ｂ）は、大信号で変調を行っ
た場合を示し、変調出力に非直線歪みが生じるため、出
力信号波形は入力信号波形と一致せず、歪みによる誤差
成分が発生する。Further, FIG. 7B shows a case where modulation is performed with a large signal, and since nonlinear distortion occurs in the modulation output, the output signal waveform does not match the input signal waveform, and an error component due to distortion is generated. Occur.
【００１３】本発明は、このような従来技術の問題点を
解決しようとするものであって、光変調器出力におけ
る、静特性の非直線性に基づく歪みによる誤差成分を検
出し、この誤差成分によって誤差信号発生用の光変調器
を駆動して発生した誤差信号光を用いて、変調光信号に
おける歪み成分を打ち消すことによって、変調光信号に
おける歪みを除去する、変調光信号の歪み補償方式を提
供することを目的としている。The present invention is intended to solve the above-mentioned problems of the prior art, and detects an error component due to distortion based on the non-linearity of the static characteristic in the output of the optical modulator, and detects this error component. By using the error signal light generated by driving the optical modulator for generating the error signal, the distortion component of the modulated optical signal is removed by canceling the distortion component in the modulated optical signal. It is intended to be provided.
【００１４】[0014]
【課題を解決するための手段】(1) 本発明は、主信号に
よって変調光信号を発生する主信号用光変調手段１に対
して、変調光信号の波形を検出する光／電気変換手段３
と、主信号波形と検出された変調光信号波形との誤差信
号を検出する誤差信号検出手段５と、検出された誤差信
号に応じて誤差信号光を発生する誤差信号用光変調手段
７とを設け、主信号用光変調手段１の変調光信号に誤差
信号用光変調手段７の誤差信号光を合成することによっ
て、変調光信号の歪みを補償するものである。(1) According to the present invention, an optical / electrical converting means 3 for detecting a waveform of a modulated optical signal is provided for an optical modulating means 1 for a main signal which generates a modulated optical signal by a main signal.
An error signal detecting means 5 for detecting an error signal between the main signal waveform and the detected modulated optical signal waveform, and an error signal light modulating means 7 for generating an error signal light in accordance with the detected error signal. It is provided to compensate the distortion of the modulated optical signal by combining the modulated optical signal of the main signal optical modulator 1 with the error signal light of the error signal optical modulator 7.
【００１５】(2) また本発明はこの場合に、主信号用光
変調手段１および誤差信号用光変調手段７が、同一光源
の発生光を変調する外部変調器からなるものである。(2) In the present invention, the main signal light modulating means 1 and the error signal light modulating means 7 are external modulators for modulating the light generated by the same light source.
【００１６】(3) また本発明はこの場合に、主信号用光
変調手段１および誤差信号用光変調手段７が、スペクト
ル特性が揃った発光素子からなるものである。(3) Further, in the present invention, the main signal light modulating means 1 and the error signal light modulating means 7 in this case are composed of light emitting elements having uniform spectral characteristics.
【００１７】[0017]
【作用】図１は、本発明の原理的構成を示したものであ
る。主信号用光変調手段１は、主信号によって主信号変
調光を発生する。光カプラ２は、主信号用光変調手段１
の主信号変調光を通過させるとともに一部を分岐する。
光／電気変換手段３は、光カプラ２で分岐された主信号
変調光を電気信号に変換する。利得制御手段４は、主信
号を利得制御して増幅する。FIG. 1 shows the principle of the present invention. The main signal light modulation means 1 generates main signal modulated light by the main signal. The optical coupler 2 is a main signal optical modulator 1
The main signal modulated light of is passed and a part is branched.
The optical / electrical converting means 3 converts the main signal modulated light branched by the optical coupler 2 into an electric signal. The gain control means 4 gain-controls and amplifies the main signal.
【００１８】誤差信号検出手段５は、利得制御手段４の
出力波形と光／電気変換手段３の出力信号波形との誤差
を検出して、誤差信号を発生する。利得制御手段６は、
誤差信号検出手段５の誤差信号出力を利得制御して増幅
する。誤差信号用光変調手段７は、利得制御手段６の出
力信号に応じて誤差信号光を発生する。光カプラ８は、
光カプラ２の主信号変調光と誤差信号用光変調手段７の
誤差信号光とを合成して、変調光信号出力を発生する。The error signal detection means 5 detects an error between the output waveform of the gain control means 4 and the output signal waveform of the optical / electrical conversion means 3 and generates an error signal. The gain control means 6 is
The error signal output of the error signal detection means 5 is gain-controlled and amplified. The error signal light modulator 7 generates error signal light in accordance with the output signal of the gain controller 6. The optical coupler 8 is
The main signal modulated light of the optical coupler 2 and the error signal light of the error signal light modulator 7 are combined to generate a modulated light signal output.
【００１９】これによって、主信号用光変調手段１が発
生する、主信号変調光の有する歪みは、誤差信号用光変
調手段７の誤差信号光によって補償されるので、主信号
用光変調手段１が有する静特性の非直線性に基づいて発
生する、変調光信号の歪みを除去することができる。As a result, the distortion of the main signal modulated light generated by the main signal optical modulator 1 is compensated by the error signal light of the error signal optical modulator 7, so that the main signal optical modulator 1 is obtained. It is possible to remove the distortion of the modulated optical signal that is generated based on the non-linearity of the static characteristics of the.
【００２０】[0020]
【実施例】図２は、本発明の一実施例を示したものであ
る。図中、２１は光源、２２は光源２１の発生光を変調
信号Ｓで変調する第１の光外部変調器、２３は光外部変
調器２２の変調光信号を通過させるとともに一部を分岐
する光分波器、２４は光分波器２３で分岐された光を電
気信号に変換する受光素子、２５は受光素子２４の出力
電流を電圧に変換する電流／電圧変換器である。DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 shows an embodiment of the present invention. In the figure, 21 is a light source, 22 is a first optical external modulator that modulates the light generated by the light source 21 with a modulation signal S, and 23 is light that allows the modulated optical signal of the optical external modulator 22 to pass through and partly branches. A demultiplexer 24 is a light receiving element that converts the light branched by the optical demultiplexer 23 into an electric signal, and 25 is a current / voltage converter that converts the output current of the light receiving element 24 into a voltage.
【００２１】２６は、変調信号Ｓの位相を制御する第１
の位相制御回路、２７は位相制御回路２６の出力を増幅
する第１の増幅器、２８は増幅器２７の出力電圧と電流
／電圧変換器２５の出力電圧との差を求める差動増幅
器、２９は差動増幅器２８の出力電圧の位相を制御する
第２の位相制御回路である。Numeral 26 is a first for controlling the phase of the modulated signal S.
Phase control circuit 27, a first amplifier for amplifying the output of the phase control circuit 26, 28 a differential amplifier for obtaining the difference between the output voltage of the amplifier 27 and the output voltage of the current / voltage converter 25, and 29 the difference It is a second phase control circuit for controlling the phase of the output voltage of the dynamic amplifier 28.
【００２２】３０は位相制御回路２９の出力を増幅する
第２の増幅器、３１は光源２１の発生光を増幅器３０の
出力によって変調する第２の光外部変調器、３２は光分
波器２３の通過光と、光外部変調器３１の発生光とを合
成する光合波器である。Reference numeral 30 is a second amplifier for amplifying the output of the phase control circuit 29, 31 is a second optical external modulator for modulating the light generated by the light source 21 by the output of the amplifier 30, and 32 is an optical demultiplexer 23. It is an optical multiplexer that combines the passing light and the light generated by the optical external modulator 31.
【００２３】光源２１から出力された光は、変調効率η
1 を有する光外部変調器２２において変調信号Ｓによっ
て変調されて、変調光出力η1 Ｓ＋ε＋Ｃ1 を発生す
る。ここでεは光外部変調器２２の変調特性の非線形領
域で発生する歪み成分、Ｃ1 は光外部変調器２２で発生
する直流（ＤＣ）光成分である。The light output from the light source 21 has a modulation efficiency η.
It is modulated by the modulation signal S in an optical external modulator 22 having a 1 to produce a modulated light output η 1 S + ε + C 1 . Here, ε is a distortion component generated in the nonlinear region of the modulation characteristic of the optical external modulator 22, and C 1 is a direct current (DC) optical component generated in the optical external modulator 22.
【００２４】この変調光出力は、光分波器２３において
Ｎ：１に分岐されて、通過光出力〔Ｎ／（Ｎ＋１）〕
（η1 Ｓ＋ε＋Ｃ1 ）と、分岐光出力〔１／（Ｎ＋
１）〕（η 1 Ｓ＋ε＋Ｃ1 ）とを生じる。This modulated light output is output by the optical demultiplexer 23.
Branched to N: 1, passing light output [N / (N + 1)]
(Η1 S + ε + C1 ) And the branched light output [1 / (N +
1)] (η 1 S + ε + C1 ) And occur.
【００２５】光分波器２３の分岐光出力は、受光素子２
４において電流信号に変換され、電流／電圧変換器２５
において電圧信号に変換されて、出力電圧〔Ｒ／（Ｎ＋
１）〕（η1 Ｓ＋ε）＋〔Ｒ／（Ｎ＋１）〕Ｃ1 を生じ
るが、このうちＤＣ成分〔Ｒ／（Ｎ＋１）〕Ｃ1 は除去
されて、交流成分〔Ｒ／（Ｎ＋１）〕（η1 Ｓ＋ε）の
みが差動増幅器２８の一方の入力に加えられる。なおこ
こでＲは、受光素子２４と電流／電圧変換器２５の変換
効率である。The branched light output of the optical demultiplexer 23 is the light receiving element 2
4 is converted into a current signal, and the current / voltage converter 25
At the output voltage [R / (N +
1)] (η 1 S + ε) + [R / (N + 1)] C 1 of which the DC component [R / (N + 1)] C 1 is removed and the AC component [R / (N + 1)] ( Only η 1 S + ε) is applied to one input of differential amplifier 28. Here, R is the conversion efficiency of the light receiving element 24 and the current / voltage converter 25.
【００２６】一方、変調信号Ｓは、位相制御回路２６で
位相を調整され、増幅器２７で増幅されて、出力Ｇ1 Ｓ
＝〔Ｒη1 ／（Ｎ＋１）〕Ｓを生じて、差動増幅器２８
の他方の入力に加えられる。ここでＧ1 は位相制御回路
２６と増幅器２７の利得で、Ｇ1 ＝Ｒη1 （Ｎ＋１）で
ある。差動増幅器２８は増幅器２７の出力と、電流／電
圧変換器２５の出力との差を求めて、誤差信号−〔Ｒ／
（Ｎ＋１）〕εを出力する。On the other hand, the phase of the modulated signal S is adjusted by the phase control circuit 26, amplified by the amplifier 27, and output G 1 S
= [Rη 1 / (N + 1)] S, and the differential amplifier 28
Is added to the other input of. Here, G 1 is the gain of the phase control circuit 26 and the amplifier 27, and G 1 = Rη 1 (N + 1). The differential amplifier 28 obtains the difference between the output of the amplifier 27 and the output of the current / voltage converter 25 and calculates the error signal − [R /
(N + 1)] ε is output.
【００２７】この際、誤差信号を正確に得るためには、
位相制御回路２６および増幅器２７によって、位相，振
幅を最適化する必要がある。なお、分岐光出力を変換し
た電気信号に含まれるＤＣ成分は、ＡＣ結合やオフセッ
ト調整によって除去することが可能であるし、また除去
しなくても、原理的には問題にならないため、無視でき
る。At this time, in order to accurately obtain the error signal,
It is necessary to optimize the phase and amplitude by the phase control circuit 26 and the amplifier 27. The DC component contained in the electrical signal obtained by converting the branched optical output can be removed by AC coupling or offset adjustment, and even if it is not removed, it does not pose a problem in principle and can be ignored. .
【００２８】位相制御回路２９は、差動増幅器２８の誤
差信号出力の位相を調整し、増幅器３０は位相制御回路
２９の出力を増幅して、出力信号−〔ＲＧ2 ／（Ｎ＋
１）〕ε＝−〔Ｎ／（Ｎ＋１）η2 〕εを発生する。こ
こでＧ2 は位相制御回路２９と増幅器３０の利得で、Ｇ
2 ＝Ｎ／η2 Ｒである。The phase control circuit 29 adjusts the phase of the error signal output of the differential amplifier 28, and the amplifier 30 amplifies the output of the phase control circuit 29 to obtain the output signal − [RG 2 / (N +
1)] ε = − [N / (N + 1) η 2 ] ε is generated. Here, G 2 is the gain of the phase control circuit 29 and the amplifier 30, and
2 = N / η 2 R.
【００２９】また光源２１から出力された光は、変調効
率η2 を有する光外部変調器３１において、増幅器３０
の出力信号によって変調されて、変調光出力−〔Ｎ／
（Ｎ＋１）〕ε＋Ｃ2 を出力する。ここでＣ2 は、光外
部変調器３１で発生する直流（ＤＣ）光成分である。The light output from the light source 21 is sent to the amplifier 30 in the optical external modulator 31 having the modulation efficiency η 2.
Modulated by the output signal of the modulated optical output- [N /
(N + 1)] ε + C 2 is output. Here, C 2 is a direct-current (DC) light component generated in the optical external modulator 31.
【００３０】光合波器３２は、光分波器２３の通過光出
力と、光外部変調器３１の出力光とを加算して、出力光
信号〔Ｎ／（Ｎ＋１）〕η1 Ｓ＋〔Ｎ／（Ｎ＋１）〕Ｃ
1 ＋Ｃ2 を生じるが、このうち第２項，第３項はＤＣ成
分であって無視することができ、これによって歪みのな
い変調光信号出力〔Ｎ／（Ｎ＋１）〕η1 Ｓが得られ
る。The optical multiplexer 32 adds the output light of the optical demultiplexer 23 and the output light of the optical external modulator 31, and outputs the output optical signal [N / (N + 1)] η 1 S + [N / (N + 1)] C
1 + C 2 is generated, of which the second and third terms are DC components and can be ignored, so that a modulated optical signal output [N / (N + 1)] η 1 S without distortion is obtained. .
【００３１】この際、正しく歪み補償を行うためには、
位相制御回路２９および増幅器３０によって、差動増幅
器２８で得られた誤差信号の位相，振幅を最適化するこ
とが必要である。At this time, in order to perform distortion compensation correctly,
It is necessary to optimize the phase and amplitude of the error signal obtained by the differential amplifier 28 by the phase control circuit 29 and the amplifier 30.
【００３２】本発明の方式は、光変調手段として、外部
変調器でなく、直接変調素子であるＬＤの場合に対して
も適用可能であるが、この場合、主信号と誤差信号の光
源が異なることになるため、スペクトラムの違いによる
ビート雑音の発生が懸念される。そこでＬＤを使用する
場合には、スペクトラル特性の揃ったものを用いる等の
配慮が必要となる。The method of the present invention can be applied not only to the external modulator but also to the LD which is the direct modulation element as the optical modulation means, but in this case, the light sources of the main signal and the error signal are different. Therefore, there is a concern that beat noise may occur due to the difference in spectrum. Therefore, when using an LD, it is necessary to take into consideration such as using one having a spectral characteristic.
【００３３】[0033]
【発明の効果】以上説明したように本発明によれば、主
信号によって発生した変調光信号の波形を検出して、主
信号波形と検出された変調光信号波形との誤差信号を求
め、この誤差信号に応じて誤差信号光を発生して、主信
号変調光信号にこの誤差信号光を合成するようにしたの
で、主信号用変調器の静特性の非直線性に基づく変調光
信号の歪みを補償して、歪みのない変調光信号出力を得
ることができる。As described above, according to the present invention, the waveform of the modulated optical signal generated by the main signal is detected to obtain the error signal between the main signal waveform and the detected modulated optical signal waveform. Since the error signal light is generated according to the error signal and this error signal light is combined with the main signal modulation light signal, the distortion of the modulation light signal based on the non-linearity of the static characteristics of the main signal modulator. Can be compensated for to obtain a modulated optical signal output without distortion.
【図１】本発明の原理的構成を示す図である。FIG. 1 is a diagram showing a principle configuration of the present invention.
【図２】本発明の一実施例を示す図である。FIG. 2 is a diagram showing an embodiment of the present invention.
【図３】従来の変調光信号発生回路の原理的構成を示す
図である。FIG. 3 is a diagram showing a principle configuration of a conventional modulated optical signal generation circuit.
【図４】半導体レーザ（ＬＤ）の静特性を例示する図で
ある。FIG. 4 is a diagram illustrating static characteristics of a semiconductor laser (LD).
【図５】電界吸収型光変調器（ＥＡＭ）の静特性を例示
する図である。FIG. 5 is a diagram illustrating static characteristics of an electro-absorption optical modulator (EAM).
【図６】ＬｉＮｂＯ3 マッハツェンダ型光変調器（Ｌ
Ｎ）の静特性を例示する図である。FIG. 6 is a LiNbO 3 Mach-Zehnder type optical modulator (L
It is a figure which illustrates the static characteristic of N).
【図７】矩形波変調の場合の変調波形を示す図であっ
て、（ａ）は小信号入力の場合を示し、（ｂ）は大信号
入力の場合を示す。7A and 7B are diagrams showing a modulation waveform in the case of rectangular wave modulation, in which FIG. 7A shows a case of small signal input, and FIG. 7B shows a case of large signal input.
１ 主信号用光変調手段 ３ 光／電気変換手段 ５ 誤差信号検出手段 ７ 誤差信号用光変調手段 DESCRIPTION OF SYMBOLS 1 Optical modulation means for main signal 3 Optical / electrical conversion means 5 Error signal detection means 7 Optical modulation means for error signals
Claims (3)
信号用光変調手段（１）に対して、 該変調光信号の波形を検出する光／電気変換手段（３）
と、 前記主信号波形と該検出された変調光信号波形との誤差
信号を検出する誤差信号検出手段（５）と、 該検出された誤差信号に応じて誤差信号光を発生する誤
差信号用光変調手段（７）とを設け、 前記主信号用光変調手段（１）の変調光信号に該誤差信
号用光変調手段（７）の誤差信号光を合成することによ
って、該変調光信号の歪みを補償することを特徴とする
変調光信号の歪み補償方式。1. An optical / electrical conversion means (3) for detecting a waveform of a modulated optical signal for a main signal optical modulation means (1) for generating a modulated optical signal by a main signal.
An error signal detecting means (5) for detecting an error signal between the main signal waveform and the detected modulated optical signal waveform, and an error signal light for generating an error signal light according to the detected error signal. Distortion of the modulated optical signal by providing a modulating means (7) and combining the modulated optical signal of the main signal optical modulating means (1) with the error signal light of the error signal optical modulating means (7). A distortion compensation method for a modulated optical signal, which is characterized by:
差信号用光変調手段（７）が、同一光源の発生光を変調
する外部変調器からなることを特徴とする請求項１に記
載の変調光信号の歪み補償方式。2. The optical modulator for main signal (1) and the optical modulator for error signal (7) are external modulators for modulating the light generated by the same light source. Compensation method for modulated optical signal.
差信号用光変調手段（７）が、スペクトル特性が揃った
発光素子からなることを特徴とする請求項１に記載の変
調光信号の歪み補償方式。3. The modulated optical signal according to claim 1, wherein the main signal optical modulation means (1) and the error signal optical modulation means (7) are light emitting elements having uniform spectral characteristics. Distortion compensation method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4177946A JPH0621898A (en) | 1992-07-06 | 1992-07-06 | Distortion compnesation system for modulated optical signal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4177946A JPH0621898A (en) | 1992-07-06 | 1992-07-06 | Distortion compnesation system for modulated optical signal |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0621898A true JPH0621898A (en) | 1994-01-28 |
Family
ID=16039846
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4177946A Withdrawn JPH0621898A (en) | 1992-07-06 | 1992-07-06 | Distortion compnesation system for modulated optical signal |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0621898A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100343141B1 (en) * | 1999-12-29 | 2002-07-05 | 윤종용 | Optical transfer system for compensating transfer loss |
| KR100859808B1 (en) * | 2007-01-05 | 2008-09-24 | 삼성전자주식회사 | Optical Network Unit for Error Detection and Recovery of Optic Module and Control Method Thereof |
-
1992
- 1992-07-06 JP JP4177946A patent/JPH0621898A/en not_active Withdrawn
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100343141B1 (en) * | 1999-12-29 | 2002-07-05 | 윤종용 | Optical transfer system for compensating transfer loss |
| US6917762B2 (en) | 1999-12-29 | 2005-07-12 | Samsung Electronics Co., Ltd. | Optical transmission system for compensating for transmission loss |
| US7146108B2 (en) | 1999-12-29 | 2006-12-05 | Samsung Electronics, Co., Ltd. | Optical transmission system for compensating for transmission loss |
| KR100859808B1 (en) * | 2007-01-05 | 2008-09-24 | 삼성전자주식회사 | Optical Network Unit for Error Detection and Recovery of Optic Module and Control Method Thereof |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 19991005 |