JP3121504B2 - Optical transmission circuit - Google Patents
Optical transmission circuitInfo
- Publication number
- JP3121504B2 JP3121504B2 JP06266584A JP26658494A JP3121504B2 JP 3121504 B2 JP3121504 B2 JP 3121504B2 JP 06266584 A JP06266584 A JP 06266584A JP 26658494 A JP26658494 A JP 26658494A JP 3121504 B2 JP3121504 B2 JP 3121504B2
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- JP
- Japan
- Prior art keywords
- optical modulator
- optical
- transmission circuit
- light
- signal
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Description
【０００１】[0001]
【産業上の利用分野】本発明は、光送信回路に関し、特
に、光映像分配システム等の低歪みが必要とされるサブ
キャリア光送信回路に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical transmission circuit, and more particularly to a subcarrier optical transmission circuit requiring low distortion, such as an optical video distribution system.
【０００２】[0002]
【従来の技術】光送信回路においては、光変調器の非線
形性歪みに対する補償を行なう必要がある。2. Description of the Related Art In an optical transmission circuit, it is necessary to compensate for nonlinear distortion of an optical modulator.
【０００３】光変調器のＶ・Ｌ特性の非線形性による歪
みの発生を補償する手段としては、フィードフォワード
歪み補償法とプリディストーション歪み補償法とが知ら
れている。As means for compensating for the generation of distortion due to the nonlinearity of the VL characteristic of an optical modulator, a feedforward distortion compensation method and a predistortion distortion compensation method are known.
【０００４】これらの内、前者のフィードフォワード歪
み補償法は、歪み成分を検出して、これを逆位相で変調
出力光に加えることにより変調器の非線形特性により発
生した歪みを補償するものである。[0004] Among them, the former feed-forward distortion compensation method detects a distortion component and adds it to the modulated output light in the opposite phase to compensate for the distortion generated due to the nonlinear characteristic of the modulator. .
【０００５】また、後者のプリディストーション歪み補
償法は、変調器と逆の非線形特性を持つ回路により、逆
位相の歪み成分を生成して、予め変調信号に加えておく
ことにより、歪みを補償するものである。これらの内、
その非線形特性が明らかでなく、素子温度等によって特
性が変化する変調器を用いる場合には、前者のフィード
フォワード歪み補償法が有効である。In the latter predistortion distortion compensating method, a distortion component having an opposite phase is generated by a circuit having a nonlinear characteristic opposite to that of a modulator, and is added to a modulation signal in advance to compensate for the distortion. Things. Of these,
In the case of using a modulator whose nonlinear characteristics are not clear and whose characteristics change depending on element temperature or the like, the former feedforward distortion compensation method is effective.
【０００６】従来のフィードフォワード歪み補償技術を
適用した光送信回路の構成方法の例を図２に示す。同図
において、数字符号１は光源、２はＦＤＭ多チャネル信
号多重化装置、３は分岐器、４は光変調器、５は分岐
器、６は主信号光、７は誤差信号検出用光、８は光電気
変換器、９，１２は増幅器、１０，１３は遅延調整管、
１１は減算器、１４はレーザダイオード、１５は可変光
強度減衰器、１６は光結合器を表わしている。FIG. 2 shows an example of a configuration method of an optical transmission circuit to which a conventional feedforward distortion compensation technique is applied. In the figure, numeral 1 is a light source, 2 is an FDM multi-channel signal multiplexer, 3 is a splitter, 4 is an optical modulator, 5 is a splitter, 6 is a main signal light, 7 is an error signal detection light, 8 is a photoelectric converter, 9 and 12 are amplifiers, 10 and 13 are delay adjusting tubes,
11 denotes a subtractor, 14 denotes a laser diode, 15 denotes a variable light intensity attenuator, and 16 denotes an optical coupler.
【０００７】以下同図を参照して、その動作を説明す
る。チャネル信号多重化装置２からの電気信号により光
変調器４において光変調される。分岐器５において分岐
された光変調器４の出力光の一部７を光電気変換器８に
おいて光電気変換し、増幅器９で振幅調整した電気信号
と、光変調器４の入力変調電気信号であるＦＤＭ多チャ
ネル信号多重化装置の出力の一部を分岐器３において分
岐し遅延調整管１０において遅延調整された電気信号と
の間で減算器１１によって減算を行うことにより誤差信
号のみを抽出する。The operation will be described below with reference to FIG. Optical modulation is performed in the optical modulator 4 by an electric signal from the channel signal multiplexing device 2. A part 7 of the output light of the optical modulator 4 branched by the splitter 5 is subjected to photoelectric conversion in the photoelectric converter 8 and the electric signal whose amplitude is adjusted by the amplifier 9 and the input modulated electric signal of the optical modulator 4 are used. A part of the output of a certain FDM multi-channel signal multiplexing device is branched by the branching device 3 and subtracted by the subtractor 11 from the electric signal whose delay has been adjusted by the delay adjusting tube 10 to extract only the error signal. .
【０００８】そして、該誤差信号を増幅器１２によって
振幅調整し、遅延調整管１３によって遅延調整を行った
後、該誤差信号によりレーザダイオード１４を光変調
し、その変調信号光を主信号光に含まれる歪み成分と同
強度になるまで可変光強度減衰器１５において振幅調整
した後、この信号を主信号光６に対し光結合器１６にお
いて逆位相で加え合わせることにより、光変調器出力の
主信号光に含まれる歪み成分を除去する。After the amplitude of the error signal is adjusted by the amplifier 12 and the delay is adjusted by the delay adjusting tube 13, the laser diode 14 is optically modulated by the error signal, and the modulated signal light is included in the main signal light. After the amplitude is adjusted by the variable optical intensity attenuator 15 until the intensity becomes the same as the distortion component to be obtained, this signal is added to the main signal light 6 in an opposite phase in the optical coupler 16 to obtain the main signal output from the optical modulator. Eliminates distortion components contained in light.
【０００９】[0009]
【発明が解決しようとする課題】上述したような従来の
フィードフォワード歪み補償技術は、これを、光映像分
配システム等の低歪みが必要とされるサブキャリア光送
信回路に適用しようとするとき、以下に述べるような、
好ましくない問題があった。When the conventional feedforward distortion compensation technique as described above is applied to a subcarrier optical transmission circuit requiring low distortion, such as an optical video distribution system, As described below,
There was an unpleasant problem.
【００１０】従来のこの方法では、光送信回路出力光
が、光変調器出力光と誤差信号光の２波長となり、これ
ら２信号光の波長差により、伝送距離に比例した遅延差
が生ずるから、光ファイバによる長距離伝送後には、歪
み除去が十分ではない状態となる。In this conventional method, the output light of the optical transmission circuit has two wavelengths, that is, the output light of the optical modulator and the error signal light, and the wavelength difference between these two signal lights causes a delay difference proportional to the transmission distance. After long-distance transmission by an optical fiber, the distortion is not sufficiently removed.
【００１１】さらに、光映像分配システムにおいて
は、光ファイバ増幅技術が必須であるが、その利得は増
幅される信号光の波長に依存して偏差を持つため、光変
調器出力光に含まれる歪み成分と誤差信号光中の歪み成
分の強度が光増幅後一致しなくなり、歪み成分の除去が
十分に行われない。Further, in the optical image distribution system, an optical fiber amplification technique is indispensable. However, since the gain has a deviation depending on the wavelength of the signal light to be amplified, the distortion included in the output light from the optical modulator is required. The component and the intensity of the distortion component in the error signal light do not match after optical amplification, and the distortion component is not sufficiently removed.
【００１２】また、前記光変調器出力光と誤差信号光
との２つの信号光の波長を等しくすると、これらの間の
ビート雑音の影響が無視できなくなり、信号光の雑音に
よる劣化が大きくなる。Further, if the wavelengths of the two signal lights, ie, the output light of the optical modulator and the error signal light, are made equal, the influence of beat noise between them cannot be ignored, and the deterioration of the signal light due to the noise increases.
【００１３】本発明は、これらの従来の課題を解決して
低歪み、低雑音が要求される系へ適用することのできる
光送信回路を提供することを目的としている。An object of the present invention is to provide an optical transmission circuit which can solve the conventional problems and can be applied to a system requiring low distortion and low noise.
【００１４】[0014]
【課題を解決するための手段】本発明によれば、上述の
課題は前記特許請求の範囲に記載した手段により解決さ
れる。According to the present invention, the above-mentioned object is solved by the means described in the claims.
【００１５】すなわち、請求項１の発明は、光変調器に
より発生する非線形歪み成分除去方法としてフィードフ
ォワード歪み補償技術を適用する光送信回路において、
光送信回路の出力部に外部光変調器を配置し、歪み成分
を含む前記光変調器の出力光を該外部光変調器に入力
し、該外部光変調器の変調電気信号として、前記光変調
器出力光の一部の光電気変換後の電気信号と該光変調器
の入力変調電気信号の差分より生成した誤差信号を前記
外部光変調器の入力光に含まれる誤差信号と逆位相とな
るように入力する構成とした光送信回路である。That is, the first aspect of the present invention is an optical transmission circuit which applies a feedforward distortion compensation technique as a method for removing a nonlinear distortion component generated by an optical modulator.
An external optical modulator is arranged at an output section of the optical transmission circuit, and output light of the optical modulator including a distortion component is input to the external optical modulator, and the optical modulation is performed as a modulated electric signal of the external optical modulator. An error signal generated from the difference between the electrical signal after photoelectric conversion of a part of the output light of the optical modulator and the input modulated electrical signal of the optical modulator has an opposite phase to the error signal included in the input light of the external optical modulator. This is an optical transmission circuit configured to input signals as described above.
【００１６】請求項２の発明は請求項１記載の発明にお
いて、光変調器としてＬＤ直接変調を用いるように構成
したものである。請求項３の発明は、請求項１記載の発
明において、光変調器を光源と光外部変調器とにより構
成したものである。According to a second aspect of the present invention, in the first aspect of the present invention, the optical modulator uses LD direct modulation. According to a third aspect of the present invention, in the first aspect, the optical modulator includes a light source and an external optical modulator.
【００１７】請求項４の発明は、前記請求項１〜請求項
３記載の発明における誤差信号を生成する手段を、光変
調器に与える電気信号の１部と、該光変調器の出力光の
１部を光電気変換して得た電気信号とをその位相が同相
となるように調整した後減算器によりその差分を取り出
すように構成したものである。According to a fourth aspect of the present invention, the means for generating an error signal according to the first to third aspects of the present invention includes a part of an electric signal supplied to an optical modulator and a part of an output light of the optical modulator. An electric signal obtained by photoelectrically converting one part is adjusted so that its phase becomes the same phase, and then the difference is extracted by a subtracter.
【００１８】請求項５の発明は、前記請求項１〜請求項
３記載の発明における誤差信号を生成する手段を、光変
調器に与える電気信号の１部と、該光変調器の出力光の
１部を光電気変換して得た電気信号とを、その互いの位
相が逆相となるように調整した後合成するように構成し
たものである。According to a fifth aspect of the present invention, the means for generating an error signal according to the first to third aspects of the present invention includes a part of an electric signal applied to an optical modulator and a part of an output light of the optical modulator. An electric signal obtained by photoelectrically converting a part of the electric signal is adjusted so that their phases are opposite to each other, and then combined.
【００１９】[0019]
【作用】上述のように、本発明は、フィードフォワード
歪み補償回路に外部光変調器を適用する構成、即ち、光
変調器出力光を外部光変調器に入力し、当該外部光変調
器を前記の誤差信号により、光変調器出力光に含まれる
歪み成分に対し逆位相で光変調することにより、光変調
器出力光に含まれる歪み成分を除去するようにしたもの
である。As described above, the present invention provides a configuration in which an external optical modulator is applied to a feedforward distortion compensation circuit, that is, an optical modulator output light is input to an external optical modulator, and the external optical modulator is connected to the external optical modulator. The optical modulator modulates the distortion component contained in the output light of the optical modulator in the opposite phase by the error signal to remove the distortion component contained in the output light of the optical modulator.
【００２０】これによって、光ファイバ伝送される光送
信回路出力光は光変調器出力光のみとなるから、従来の
フィードフォワード歪み補償回路を適用した光送信回路
では避けることのできなかった前記３点の問題、As a result, the output light of the optical transmission circuit transmitted through the optical fiber is only the output light of the optical modulator. Therefore, the above three points cannot be avoided in the optical transmission circuit to which the conventional feedforward distortion compensation circuit is applied. Problem of,
【００２１】すなわち、従来のフィードフォワード歪み
補償回路による方法では、光送信回路出力光が、光変調
器出力光と誤差信号光の２波長となり、これら２信号光
の波長差により、伝送距離に比例した遅延差が生じて、
光ファイバによる長距離伝送後には、歪み除去が十分に
行なわれなくなること、That is, in the conventional method using the feedforward distortion compensating circuit, the output light of the optical transmission circuit has two wavelengths, that is, the output light of the optical modulator and the error signal light, and is proportional to the transmission distance by the wavelength difference between these two signal lights. Delay difference,
After long-distance transmission by optical fiber, distortion is not sufficiently removed,
【００２２】さらに、光映像分配システムにおいは、光
ファイバ増幅技術が必須であるが、その利得は、増幅さ
れる信号光の波長に依存して偏差を持つため、光変調器
出力光に含まれる歪み成分と、誤差信号光中の歪み成分
の強度が光増幅後一致しなくなり、歪み成分の除去が十
分に行われないこと、および、Further, in the optical image distribution system, an optical fiber amplification technique is indispensable, but since the gain has a deviation depending on the wavelength of the signal light to be amplified, it is included in the output light from the optical modulator. The distortion component and the intensity of the distortion component in the error signal light do not match after optical amplification, and the distortion component is not sufficiently removed; and
【００２３】前記光変調器出力光と誤差信号光との２つ
の信号光の波長を等しくすると、これらの間のビート雑
音の影響が無視できなくなり、信号光の雑音による劣化
が大きくなること。等の不都合を解消することができ
る。If the wavelengths of the two signal lights, the output light of the optical modulator and the error signal light, are made equal, the influence of beat noise between them cannot be ignored, and the deterioration due to the noise of the signal light increases. And the like can be eliminated.
【００２４】[0024]
【実施例】図１は本発明の一実施例を示す図であって、
図中の太線は光線路を、また、細線は電気経路を表わし
ている。同図において、数字符号１は光源、２はＦＤＭ
多チャネル信号多重化装置、３は分岐器、４は光変調
器、５は分岐器、６は主信号光、７は誤差信号検出用
光、８は光電気変換器、９，１２は増幅器、１０，１３
は遅延調整管、１１は減算器、１７は外部光変調器を表
わしている。FIG. 1 shows an embodiment of the present invention.
The bold line in the figure indicates an optical path, and the thin line indicates an electric path. In the figure, numeral 1 denotes a light source, 2 denotes an FDM.
Multi-channel signal multiplexing device, 3 is a branching device, 4 is an optical modulator, 5 is a branching device, 6 is a main signal light, 7 is an error signal detecting light, 8 is a photoelectric converter, 9 and 12 are amplifiers, 10,13
Denotes a delay adjusting tube, 11 denotes a subtractor, and 17 denotes an external light modulator.
【００２５】以下同図を参照してその動作を説明する。
光源１からの出力光は多チャネル信号多重化装置２から
の電気信号により光変調器４において光変調される。該
光変調器４の出力光は、分岐器５において主信号光６と
誤差信号を検出するための光７に分離される。The operation will be described below with reference to FIG.
Output light from the light source 1 is optically modulated in the optical modulator 4 by an electric signal from the multi-channel signal multiplexing device 2. The output light of the optical modulator 4 is split by a splitter 5 into a main signal light 6 and a light 7 for detecting an error signal.
【００２６】後者の誤差信号検出用光７は光電気変換器
８によって光電気変換され、増幅器９で振幅調整後、分
岐器３により分岐されて遅延調整管１０で遅延調整され
た歪み成分を含まない多チャネル信号（信号源はＦＤＭ
多チャネル信号多重化装置２の出力）との間で減算器１
１において減算を行うことにより、誤差信号のみを抽出
する。The latter error signal detecting light 7 is subjected to photoelectric conversion by a photoelectric converter 8, the amplitude of which is adjusted by an amplifier 9, the signal is branched by a splitter 3, and contains a distortion component whose delay is adjusted by a delay adjusting tube 10. No multi-channel signal (signal source is FDM
Output from the multi-channel signal multiplexer 2)
By performing the subtraction in 1, only the error signal is extracted.
【００２７】そして、当該誤差信号を増幅器１２によっ
て主信号光中の歪み成分の振幅に等しくなるまで増幅
し、遅延調整管１３で遅延調整後、歪み成分除去用の外
部変調器１７に変調信号として主信号光６に含まれる歪
み成分に対して逆位相となるように入力して、外部光変
調器を通過する主信号光６に含まれる歪み成分を除去す
る。Then, the error signal is amplified by the amplifier 12 until it becomes equal to the amplitude of the distortion component in the main signal light, the delay is adjusted by the delay adjusting tube 13, and the modulated signal is output to the external modulator 17 for removing the distortion component. The distortion component included in the main signal light 6 is input so as to have an opposite phase to the distortion component included in the main signal light 6, and the distortion component included in the main signal light 6 passing through the external optical modulator is removed.
【００２８】本実施例は、光源１と光変調器４を別に設
ける場合について示しているが、これに限るものではな
く、ＬＤ直接変調を用いる構成としても全く同様な効果
が得られることは言うまでもない。Although the present embodiment shows a case where the light source 1 and the optical modulator 4 are separately provided, the present invention is not limited to this, and it goes without saying that the same effect can be obtained by using a direct LD modulation. No.
【００２９】また、本実施例では誤差信号を取り出す手
段として、光変調器に与える電気信号の１部と、該光変
調器の出力光の１部を光電気変換して得た電気信号とを
その位相が同相となるように調整した後、減算器により
その差分を取り出す方法を採っているが誤差信号を取り
出す手段は、これに限るものではない。In this embodiment, as a means for extracting an error signal, a part of an electric signal to be given to the optical modulator and an electric signal obtained by photoelectrically converting a part of the output light of the optical modulator are used. After adjusting the phases so that they are in phase, a method of extracting the difference by a subtractor is employed, but the means for extracting the error signal is not limited to this.
【００３０】例えば、光変調器に与える電気信号の１部
と、該光変調器の出力光の１部を光電気変換して得た電
気信号とをその位相が逆相となるように調整した後、こ
れらを合成することによって、誤差信号を抽出するもの
であっても良い。For example, a part of the electric signal given to the optical modulator and an electric signal obtained by photoelectrically converting a part of the output light of the optical modulator are adjusted so that the phases are opposite. Thereafter, an error signal may be extracted by combining these.
【００３１】本発明の原理は既に述べたように、光変調
器の出力光の一部を取り出して、これを光電気変換し、
これと、該光変調器の入力である電気信号との誤差信号
を取り出して、これを光伝送路の出力側に設けた外部光
変調器に、該外部光変調器に入力される主信号光に含ま
れる誤差信号と逆位相になるように加えることによっ
て、目的を達するものである。As described above, the principle of the present invention is to take out a part of the output light of the optical modulator and to perform photoelectric conversion on this part.
An error signal between this signal and an electric signal input to the optical modulator is extracted, and the extracted signal is supplied to an external optical modulator provided on the output side of the optical transmission line, and the main signal light input to the external optical modulator is output. The purpose is achieved by adding the signal so as to be in the opposite phase to the error signal included in.
【００３２】従って、これを実現する回路構成は、図
１、あるいは、上記説明で開示した態様に限定されるも
のではなく、回路中の機能素子の他のものへの代替、あ
るいは、位置関係の置換、さらには、位相器などの挿入
等の回路構成上の変更も本発明に含まれるものであるこ
とは言うまでもない。Therefore, the circuit configuration for realizing this is not limited to the embodiment shown in FIG. 1 or the above description, and the functional element in the circuit is replaced with another one, or the positional relationship is not limited. It goes without saying that the present invention also includes changes in the circuit configuration such as replacement and further insertion of a phase shifter and the like.
【００３３】[0033]
【発明の効果】以上説明した様に、本発明によれば、歪
み成分除去効果は光ファイバ伝送距離に関係なく発揮さ
れ、光ファイバ増幅技術との併用も可能であることか
ら、低歪み、低雑音が要求される光映像分配システム等
において、その特性を十分に生かすことが出来る利点が
ある。As described above, according to the present invention, the distortion component removing effect is exhibited irrespective of the optical fiber transmission distance, and can be used in combination with the optical fiber amplification technology. In an optical image distribution system or the like that requires noise, there is an advantage that its characteristics can be fully utilized.
【図１】本発明の一実施例を示す図である。FIG. 1 is a diagram showing one embodiment of the present invention.
【図２】従来のフィードフォワード歪み補償技術を適用
した光送信回路の例を示す図である。FIG. 2 is a diagram illustrating an example of an optical transmission circuit to which a conventional feedforward distortion compensation technique is applied.
１ 光源 ２ ＦＤＭ多チャネル信号多重化装置 ３ 分岐器 ４ 光変調器 ５ 分岐器 ６ 主信号光 ７ 誤差信号検出用光 ８ 光電気変換器 ９，１２ 増幅器 １０，１３ 遅延調整管 １４ レーザダイオード １５ 可変強度減衰器 １６ 光結合器 １７ 外部光変調器 REFERENCE SIGNS LIST 1 light source 2 FDM multi-channel signal multiplexer 3 splitter 4 optical modulator 5 splitter 6 main signal light 7 error signal detecting light 8 photoelectric converter 9, 12 amplifier 10, 13 delay adjusting tube 14 laser diode 15 variable Intensity attenuator 16 Optical coupler 17 External light modulator
フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ Ｈ０４Ｂ 10/26 10/28 (56)参考文献 特開 平５−300099（ＪＰ，Ａ) 特開 平３−104331（ＪＰ，Ａ) 特開 平４−306025（ＪＰ，Ａ) 特開 平３−122613（ＪＰ，Ａ) 特開 平６−21898（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) H04B 10/00 - 10/28 Continuation of the front page (51) Int.Cl. 7 Identification symbol FI H04B 10/26 10/28 (56) References JP-A-5-300099 (JP, A) JP-A-3-104331 (JP, A) JP-A-4-306025 (JP, A) JP-A-3-122613 (JP, A) JP-A-6-21898 (JP, A) (58) Fields investigated (Int. Cl. 7 , DB name) H04B 10 / 00-10/28
Claims (5)
除去方法としてフィードフォワード歪み補償技術を適用
する光送信回路において、光送信回路の出力部に外部光
変調器を配置し、歪み成分を含む前記光変調器の出力光
を該外部光変調器に入力し、該外部光変調器の変調電気
信号として、前記光変調器出力光の一部の光電気変換後
の電気信号と該光変調器の入力変調電気信号の差分より
生成した誤差信号を前記外部光変調器の入力光に含まれ
る誤差信号と逆位相となるように入力する構成としたこ
とを特徴とする光送信回路。1. An optical transmission circuit to which a feedforward distortion compensation technique is applied as a method for removing a nonlinear distortion component generated by an optical modulator, wherein an external optical modulator is arranged at an output section of the optical transmission circuit, and the optical modulator includes a distortion component. The output light of the optical modulator is input to the external optical modulator, and as a modulated electric signal of the external optical modulator, an electric signal after photoelectric conversion of a part of the output light of the optical modulator and the electric signal of the optical modulator. An optical transmission circuit, wherein an error signal generated from the difference between the input modulated electric signals is input so as to have a phase opposite to that of the error signal included in the input light of the external optical modulator.
記載の光送信回路。2. The optical modulator according to claim 1, wherein the optical modulator is an LD direct modulation.
An optical transmission circuit as described in the above.
る請求項１記載の光送信回路。3. The optical transmission circuit according to claim 1, wherein the optical modulator comprises a light source and an external optical modulator.
与える電気信号の１部と、該光変調器の出力光の１部を
光電気変換して得た電気信号とをその位相が同相となる
ように調整した後減算器によりその差分を取り出すもの
である請求項１〜請求項３記載の光送信回路。And means for generating an error signal, wherein a part of the electric signal to be supplied to the optical modulator and an electric signal obtained by photoelectrically converting a part of the output light of the optical modulator have phases different from each other. 4. The optical transmission circuit according to claim 1, wherein the difference is taken out by a subtractor after the adjustment is made to be in phase.
与える電気信号の１部と、該光変調器の出力光の１部を
光電気変換して得た電気信号とを、その互いの位相が逆
相となるように調整した後合成するものである請求項１
〜請求項３記載の光送信回路。5. An apparatus for generating an error signal, comprising: converting a part of an electric signal to be supplied to an optical modulator and an electric signal obtained by photoelectrically converting a part of output light of the optical modulator into each other; 2. The method of claim 1, wherein the signals are combined after being adjusted so that the phases are opposite to each other.
An optical transmission circuit according to claim 3.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP06266584A JP3121504B2 (en) | 1994-10-31 | 1994-10-31 | Optical transmission circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP06266584A JP3121504B2 (en) | 1994-10-31 | 1994-10-31 | Optical transmission circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08130503A JPH08130503A (en) | 1996-05-21 |
| JP3121504B2 true JP3121504B2 (en) | 2001-01-09 |
Family
ID=17432842
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP06266584A Expired - Lifetime JP3121504B2 (en) | 1994-10-31 | 1994-10-31 | Optical transmission circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3121504B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7848661B2 (en) * | 2005-03-15 | 2010-12-07 | Emcore Corporation | Directly modulated laser optical transmission system with phase modulation |
| TW200840362A (en) * | 2007-03-28 | 2008-10-01 | Emcore Corp | Externally modulated laser optical transmission system with feed forward noise cancellation |
| KR101239240B1 (en) * | 2011-11-30 | 2013-03-06 | 한국과학기술원 | Noise suppression apparatus for injection seeded optical source and wavelength division multiplexed-passive optical network system having the same |
| CN105181597A (en) * | 2015-08-04 | 2015-12-23 | 宁波摩米创新工场电子科技有限公司 | High speed difference based digital photoelectric detection system |
| CN105180979A (en) * | 2015-08-04 | 2015-12-23 | 宁波摩米创新工场电子科技有限公司 | High-speed differential digital photoelectrical detecting system based on linear modulation and demodulation circuit |
-
1994
- 1994-10-31 JP JP06266584A patent/JP3121504B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH08130503A (en) | 1996-05-21 |
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