WO2012128279A1 - Multiplexed light transmitter, transmitter, receiver, and multiplexed light transmission method - Google Patents

Multiplexed light transmitter, transmitter, receiver, and multiplexed light transmission method Download PDF

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Publication number
WO2012128279A1
WO2012128279A1 PCT/JP2012/057145 JP2012057145W WO2012128279A1 WO 2012128279 A1 WO2012128279 A1 WO 2012128279A1 JP 2012057145 W JP2012057145 W JP 2012057145W WO 2012128279 A1 WO2012128279 A1 WO 2012128279A1
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light
signal
polarization
optical
transmitter
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PCT/JP2012/057145
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French (fr)
Japanese (ja)
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誠 石黒
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日本電気株式会社
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/06—Polarisation multiplex systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/60—Receivers
    • H04B10/61—Coherent receivers
    • H04B10/614—Coherent receivers comprising one or more polarization beam splitters, e.g. polarization multiplexed [PolMux] X-PSK coherent receivers, polarization diversity heterodyne coherent receivers

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  • the present invention relates to a multiplexed optical transmission apparatus, a transmitter, a receiver, and a multiplexed optical transmission method, and more particularly to a multiplexed optical transmission apparatus, a transmitter, a receiver, and a multiplexed optical transmission method that perform optical transmission by multiplexing signals by wavelength multiplexing. .
  • FIG. 1 is a block diagram showing a configuration example of a multiplex optical transmission apparatus as a background art.
  • a long-distance optical transmission transmitter 101 converts a signal from the optical transmission apparatus transmitter 1 into an optical signal having a required wavelength (first wavelength) and optical output for long-distance optical communication, and performs signal multiplexing. Output to the unit 103.
  • the long-distance optical transmission transmitter 102 converts the signal from the optical transmission apparatus transmitter 2 into an optical signal having a required wavelength (second wavelength) and optical output for long-distance optical communication, and a signal multiplexing unit.
  • second wavelength second wavelength
  • the optical signal output from the signal multiplexing unit 103 passes through the optical transmission path 104 and is separated into each wavelength by the signal separation unit 105.
  • the signal of the first wavelength is received by the long-distance optical transmission receiver 106 and transmitted to the optical transmission device receiver 3.
  • the signal of the second wavelength is received by the long-distance optical transmission receiver 107 and transmitted to the optical transmission apparatus receiver 4.
  • Patent Document 1 discloses an optical signal including a first sideband and a first optical carrier wave of the same polarization, and a second sideband and a second optical carrier wave.
  • An optical communication system is described that includes an optical transmitter to generate and an optical receiver that receives an optical signal and converts it to an electrical signal after removing the first or second optical carrier.
  • Patent Document 2 describes a method for determining a discrimination threshold of a received signal input from an optical transmission line.
  • signals are multiplexed by wavelength multiplexing.
  • signals that can be multiplexed are determined by the width of the spectrum, it was not possible to multiplex more than a predetermined number of wavelengths.
  • the present invention has been made to solve such a problem, and an object of the present invention is to increase the multiplexing density as compared with the related art.
  • a typical multiple optical transmission apparatus is: A plurality of light sources that emit light having different wavelengths, a plurality of polarizing elements that are respectively provided corresponding to the plurality of light sources, and that use a plurality of light from the plurality of light sources as light in at least two polarization directions; A plurality of optical signal modulators that are provided corresponding to each of the polarizing elements, input light from each of the plurality of polarizing elements and an information signal, and output an optical signal in which the light is modulated by the information signal; An optical transmitter including a signal multiplexing unit that multiplexes and outputs optical signals from a plurality of optical signal modulators, and A signal separation unit that separates the optical signal received from the optical transmitter for each wavelength, and the light of one of the at least two polarization directions out of the separated optical signal. A plurality of polarization controllers; and a receiver comprising: Is provided.
  • a typical optical transmitter includes a plurality of light sources that emit light having different wavelengths, and a plurality of light sources that correspond to the plurality of light sources, respectively, and the light from the plurality of light sources is polarized in at least two directions.
  • Light that is provided in correspondence with each of the plurality of polarizing elements, and the light from each of the plurality of polarizing elements and the information signal are input, and the light is modulated by the information signal
  • a plurality of optical signal modulators for outputting signals
  • a signal multiplexing unit for multiplexing and outputting optical signals from the plurality of optical signal modulators.
  • a typical receiver receives an optical signal obtained by multiplexing light of a plurality of wavelengths polarized in at least two polarization directions, and separates the optical signal for each wavelength. And a plurality of polarization controllers that respectively pass light in one polarization direction out of the light in the polarization directions in at least two directions among the optical signals that have been signal-separated.
  • a typical multiplexed optical transmission method is as follows.
  • light having different wavelengths is emitted from a plurality of light sources, and the plurality of lights from the plurality of light sources are converted to light having at least two polarization directions, and signals are obtained using polarized light and information signals.
  • the optical signal received from the optical transmitter is separated for each wavelength, and the separated optical signal is set as light in one polarization direction among the light in the at least two polarization directions.
  • the first effect is that the multiplexing density can be increased by utilizing the polarization characteristics of light.
  • the second effect is that the number of polarization axes can be changed according to the number of multiplexing by controlling the polarization.
  • FIG. 1 is a block diagram illustrating a configuration example of a multiplex optical transmission apparatus as a background art.
  • FIG. 2 is a block diagram showing an embodiment of a transmitter according to the present invention.
  • FIG. 3 is a block diagram showing an embodiment of a receiver according to the present invention.
  • FIG. 4 is a diagram illustrating an arrangement example of the arrangement of wavelength and polarization.
  • FIG. 5 is a flowchart showing a multiplexed optical transmission method by the multiplexed optical transmission apparatus according to the present invention.
  • One embodiment of a multiplex optical transmission apparatus is such that the transmitter (optical transmitter) shown in FIG. 2 and the receiver (optical receiver) shown in FIG. 3 are connected by an optical transmission line such as an optical fiber. Composed.
  • the transmitter shown in FIG. 2 includes laser diodes (LDs) 11 and 111, polarization filters 12 and 112, optical signal modulators 13 and 113, optical / electrical signal conversion circuits 14 and 114, and a signal multiplexing unit 15. It has.
  • LDs laser diodes
  • polarization filters 12 and 112 polarization filters
  • optical signal modulators 13 and 113 optical signal modulators
  • optical / electrical signal conversion circuits 14 and 114 optical / electrical signal conversion circuits
  • the laser diodes 11 and 111 are light sources that emit light having different wavelengths.
  • the laser diode 11 outputs an optical signal (CW light) having a specific wavelength ⁇ 1
  • the laser diode 111 outputs an optical signal (CW light) having a specific wavelength ⁇ 2 different from the wavelength ⁇ 1.
  • the polarization filters 12 and 112 are polarization elements that are provided corresponding to the laser diodes 11 and 111, respectively, and convert the optical signals from the laser diodes 11 and 111 into optical signals having at least two polarization directions.
  • the polarization direction of the polarization filter 12 is different from the polarization direction of the polarization filter 112.
  • the polarization filter 12 converts input light into light having a polarization characteristic in the y direction (y polarization), and the polarization filter 112 converts input light into light having a polarization characteristic in the x direction (x polarization).
  • the optical / electrical signal conversion circuits 14 and 114 are photoelectric converters that convert an optical signal input to the transmitter into an electrical signal.
  • the converted electric signal is called an information signal.
  • the optical signal modulators 13 and 113 are provided corresponding to the polarization filters 12 and 112, respectively, and optical signals from the polarization filters 12 and 112 and information signals from the optical / electrical signal conversion circuits 14 and 114, respectively. And an optical modulation signal obtained by modulating the optical signal with the information signal is output.
  • the optical signal modulator 13 outputs an optical modulation signal having y polarization characteristics
  • the optical signal modulator 113 outputs an optical modulation signal having x polarization characteristics.
  • the signal multiplexer 15 multiplexes and outputs the optical modulation signals from the optical signal modulators 13 and 113.
  • the signal multiplexing unit 15 is configured by a multiplexer, for example.
  • the receiver shown in FIG. 3 includes a signal separation unit 50, polarization controllers 61 and 161, laser diodes (LD) 62 and 162, polarization filters 63 and 163, couplers 64 and 164, and receivers 65 and 165.
  • the signal separator 50 receives the optical signal from the transmitter and separates the optical signal for each wavelength.
  • the transmitter transmits an optical signal in which light of a plurality of wavelengths polarized in at least two polarization directions is multiplexed.
  • an optical signal in which an optical modulation signal having a wavelength ⁇ 1 having y-polarization characteristics and an optical modulation signal having a wavelength ⁇ 2 having x-polarization characteristics is multiplexed is transmitted.
  • the signal separation unit 50 separates this optical signal for each wavelength.
  • the signal multiplexing unit 50 is configured by a demultiplexer, for example.
  • the polarization controllers 61 and 161 pass light in one polarization direction among the above-described light in at least two polarization directions from among the separated optical signals.
  • the polarization direction of the light that the polarization controller 61 passes is different from the polarization direction of the light that the polarization controller 161 passes.
  • the polarization controller 61 allows light having y-polarization characteristics to pass
  • the polarization controller 161 allows light having x-polarization characteristics to pass.
  • the laser diodes 62 and 162 are the same light sources as the laser diodes 11 and 111 of the transmitter, respectively.
  • the laser diode 62 outputs local CW light having a specific wavelength ⁇ 1
  • the laser diode 162 outputs local CW light having a specific wavelength ⁇ 2 different from the wavelength ⁇ 1.
  • the polarizing filters 63 and 163 are the same polarizing elements as the polarizing filters 12 and 112 of the transmitter, respectively.
  • the couplers 64 and 164 superimpose the signal light input from each of the polarization controllers 61 and 161 and the local CW light input from each of the polarization filters 63 and 163.
  • the receivers 65 and 165 demodulate the optical modulation signal by coherent reception to obtain an information signal including an electrical signal.
  • Frame detectors 66 and 166 perform frame detection on the demodulated information signal.
  • the error detectors 67 and 167 detect an error in the demodulated information signal based on the result of frame detection.
  • the polarization control circuits 68 and 168 are polarization control units that control the polarization of the polarization controllers 61 and 161 so that information signal errors are suppressed based on the error detection result.
  • the optical / electrical converters 69 and 169 convert the information signal from an electrical signal to an optical signal and output it.
  • the optical signal of the specific wavelength ⁇ 1 of the laser diode (LD) 11 is input to the polarization filter 12 (step S211).
  • the optical signal input to the polarization filter 12 is converted into an optical signal having a polarization characteristic in the y direction (y-polarized light) and input to the optical signal modulator 13 (step S212).
  • the optical signal input to the transmitter is converted into an electrical signal by the optical / electrical signal conversion circuit 14 to generate an information signal. This information signal is also input to the optical signal modulator 13 (step S212).
  • the optical signal modulator 13 performs signal modulation using the polarized optical signal and the information signal, and an optical modulation signal having a wavelength ⁇ 1 having y polarization characteristics is input to the signal multiplexing unit 15 (step S 213). ).
  • the optical signal of the specific wavelength ⁇ 2 of the laser diode (LD) 111 is input to the polarization filter 112 (step S211).
  • the optical signal input to the polarization filter 112 is converted into an optical signal having x-direction polarization characteristics (x-polarized light) and input to the optical signal modulator 113 (step S212).
  • another optical signal input to the transmitter is converted into an electrical signal by the optical / electrical signal conversion circuit 114, and an information signal is generated. This information signal is also input to the optical signal modulator 113 (step S212).
  • the optical signal modulator 113 performs signal modulation using the polarized optical signal and the information signal, and an optical modulation signal having a wavelength ⁇ 2 having x polarization characteristics is input to the signal multiplexing unit 15 (step S213). ).
  • the light modulation signal having the y polarization characteristic and the light modulation signal having the x polarization characteristic are multiplexed by the signal multiplexing unit 15 and transmitted to the receiver via the optical transmission path (step S213).
  • the optical signal transmitted from the transmitter shown in FIG. 2 is received by the receiver shown in FIG.
  • the received optical signal is separated for each wavelength by the signal separation unit 50 (step S214).
  • the optical signal of wavelength ⁇ 1 separated by the signal separation unit 50 is input to the polarization controller 61, and only the optical signal of the desired polarization (y polarization) passes through the polarization controller 61 (step S215) and is input to the coupler 64. (Step S216).
  • the local CW light of the specific wavelength ⁇ 1 of the laser diode (LD) 62 is input to the polarization filter 63, and only the light having the desired polarization (y polarization) passes through the polarization filter 63 and is input to the coupler 64 (step). S216).
  • the coupler 64 superimposes the signal light and the local light, so that the receiver 65 performs coherent reception (step S217), and the information signal including the electric signal is demodulated.
  • This information signal is converted from an electrical signal to an optical signal by a subsequent optical / electrical converter 69 via the frame detector 66 and output as an optical signal.
  • the information signal is subjected to frame detection by the frame detector 66, and then error detection is performed by the error detector 67.
  • the polarization control circuit 68 controls the polarization of the polarization controller 61 so that the error is minimized.
  • the optical signal of wavelength ⁇ 2 separated by the signal separation unit 50 is input to the polarization controller 161, and only the optical signal of desired polarization (x polarization) passes through the polarization controller 161 (step S215), and the coupler 164 (Step S216).
  • the local CW light of the specific wavelength ⁇ 2 of the laser diode (LD) 162 is input to the polarization filter 163, and only the light of the desired polarization (x polarization) passes through the polarization filter 163 and is input to the coupler 164 (step). S216).
  • the signal light and the local light are superimposed by the coupler 164, so that coherent reception is performed by the receiver 165 (step S217), and an information signal including an electric signal is demodulated.
  • This information signal is converted from an electrical signal to an optical signal by a subsequent optical / electrical converter 169 via a frame detector 166 and output as an optical signal.
  • the information signal is subjected to frame detection by the frame detector 166, and then error detection is performed by the error detector 167. Then, the polarization controller 161 controls the polarization of the polarization controller 161 so that the error is minimized.
  • the polarization directions are only x-polarized light and y-polarized light, but the number of multiplexing may be increased by using three or more polarization directions by narrowing the angular interval of the polarization direction.
  • optical signals with wavelengths ⁇ 1 and ⁇ 2 are multiplexed.
  • a transmitter that multiplexes optical signals with a larger number of wavelengths and a receiver that separates them are configured.
  • an optical signal having a wavelength of ⁇ 1 to ⁇ 6 may be multiplexed by a transmitter, and the multiplexed signal may be separated by a receiver.
  • optical signals of seven or more wavelengths may be multiplexed by the transmitter, and the multiplexed signal may be separated by the receiver.
  • ⁇ 1, ⁇ 3, and ⁇ 5 are y-polarized light with a wavelength interval of 50 GHz
  • ⁇ 2, ⁇ 4, and ⁇ 6 are x-polarized light with a wavelength interval of 50 GHz.
  • ⁇ 1, ⁇ 2, ⁇ 3, ⁇ 4, ⁇ 5, and ⁇ 6 can be arranged at a wavelength interval of 25 GHz.
  • the signal density that can be multiplexed can be increased by performing multiplexing using wavelength polarization and polarization of light in the long-distance optical transmission apparatus.
  • a plurality of light sources that emit light having different wavelengths, a plurality of polarizing elements that are provided corresponding to the plurality of light sources, and that use the light from the plurality of light sources as light in at least two polarization directions;
  • a plurality of optical signal modulators provided corresponding to the plurality of polarizing elements, to which light and information signals from the respective polarizing elements are respectively input, and optical signals from the plurality of optical signal modulators are multiplexed.
  • An optical transmitter comprising: a signal multiplexing unit; A signal separation unit that separates an optical signal received from the optical transmitter for each wavelength; and a light in one polarization direction among the light in the polarization directions in at least two directions among the optical signals that have been separated.
  • a receiver having a plurality of polarization controllers to pass;
  • Multiplexed optical transmission apparatus having
  • Appendix 2 In the multiplexed optical transmission apparatus according to appendix 1, an error detector that detects an error in an information signal demodulated from the optical signals of the plurality of polarization controllers, and a polarization control that controls the polarization of the polarization controller so as to suppress the errors A multiple optical transmission device.
  • An optical transmitter comprising: a signal multiplexing unit;
  • a receiver comprising: a plurality of polarization controllers that respectively pass light in one polarization direction out of light in two polarization directions.
  • Appendix 5 In the receiver of Appendix 4, an error detector that detects an error in an information signal demodulated from the optical signals of the plurality of polarization controllers, and a polarization controller that controls the polarization of the polarization controller so as to suppress the errors, Having a receiver.
  • an optical transmitter In an optical transmitter, light having different wavelengths is emitted from a plurality of light sources, the plurality of lights from the plurality of light sources are set as light in at least two polarization directions, and the polarized light and the information signal are used. Performs signal modulation, multiplexes and transmits a plurality of optical signals each modulated, In the receiver, the optical signal received from the optical transmitter is signal-separated for each wavelength, and the optical signal thus separated is used as light having one polarization direction out of the light having at least two polarization directions.
  • Optical transmission method In an optical transmitter, light having different wavelengths is emitted from a plurality of light sources, the plurality of lights from the plurality of light sources are set as light in at least two polarization directions, and the polarized light and the information signal are used. Performs signal modulation, multiplexes and transmits a plurality of optical signals each modulated.
  • the optical signal received from the optical transmitter is signal-separated for each wavelength, and
  • the present invention is used for a multiplexed optical transmission apparatus, a transmitter, a receiver, and a multiplexed optical transmission method for multiplexing and transmitting signals and separating received multiplexed signals for optical communication.

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Abstract

A light transmitter is provided with: two laser diodes (11, 111) for emitting light at respective wavelengths (λ1, λ2); two polarization filters (12, 112) for producing y-polarized light and x-polarized light from the light from the two laser diodes; and a signal multiplexer (15) for multiplexing and outputting the light transmitted through the two polarization filters. The receiver is provided with: a signal separator for separating the light transmitted from the light transmitter into separate signals for each wavelength; and two polarization controllers for transmitting the y-polarized light and x-polarized light from among the light signals subjected to signal separation. It is therefore possible to increase the signal density at which multiplexing can be performed, by carrying out wavelength multiplexing and also carrying out multiplexing using polarized light.

Description

多重光伝送装置、送信機、受信機及び多重光伝送方法Multiplex optical transmission apparatus, transmitter, receiver, and multiple optical transmission method
　本発明は多重光伝送装置、送信機、受信機及び多重光伝送方法に係わり、特に波長多重により信号を多重して光伝送を行う多重光伝送装置、送信機、受信機及び多重光伝送方法に関する。 The present invention relates to a multiplexed optical transmission apparatus, a transmitter, a receiver, and a multiplexed optical transmission method, and more particularly to a multiplexed optical transmission apparatus, a transmitter, a receiver, and a multiplexed optical transmission method that perform optical transmission by multiplexing signals by wavelength multiplexing. .
　図１は背景技術となる多重光伝送装置の構成例を示すブロック図である。図１において、長距離光伝送送信機１０１は光伝送装置送信機１からの信号を、長距離光通信用に所要の波長（第１の波長）と光出力の光信号に変換し、信号多重部１０３へ出力する。同様に、長距離光伝送送信機１０２は光伝送装置送信機２からの信号を、長距離光通信用に所要の波長（第２の波長）と光出力の光信号に変換し、信号多重部１０３へ出力する。 FIG. 1 is a block diagram showing a configuration example of a multiplex optical transmission apparatus as a background art. In FIG. 1, a long-distance optical transmission transmitter 101 converts a signal from the optical transmission apparatus transmitter 1 into an optical signal having a required wavelength (first wavelength) and optical output for long-distance optical communication, and performs signal multiplexing. Output to the unit 103. Similarly, the long-distance optical transmission transmitter 102 converts the signal from the optical transmission apparatus transmitter 2 into an optical signal having a required wavelength (second wavelength) and optical output for long-distance optical communication, and a signal multiplexing unit. To 103.
　信号多重部１０３から出力された光信号は、光伝送路１０４を通り、信号分離部１０５で各波長に分離される。第１の波長の信号は長距離光伝送受信器１０６で受信され、光伝送装置受信機３へ送信される。同様に、第２の波長の信号は長距離光伝送受信器１０７で受信され、光伝送装置受信機４へ送信される。 The optical signal output from the signal multiplexing unit 103 passes through the optical transmission path 104 and is separated into each wavelength by the signal separation unit 105. The signal of the first wavelength is received by the long-distance optical transmission receiver 106 and transmitted to the optical transmission device receiver 3. Similarly, the signal of the second wavelength is received by the long-distance optical transmission receiver 107 and transmitted to the optical transmission apparatus receiver 4.
　こうして、光伝送装置送信機１と光伝送装置受信機３との間、および、光伝送装置送信機２と光伝送装置受信機４のと間に、長距離光伝送装置を挿入することで、長距離離れた区間での通信が可能となることは一般的に知られている。 Thus, by inserting the long-distance optical transmission device between the optical transmission device transmitter 1 and the optical transmission device receiver 3 and between the optical transmission device transmitter 2 and the optical transmission device receiver 4, It is generally known that communication in a section that is separated by a long distance is possible.
　多重光伝送装置に関連する技術としては、特許文献１に同一偏波の第１の側波帯及び第１の光搬送波、並びに第２の側波帯及び第２の光搬送波を含む光信号を生成する光送信装置と、光信号を受信して第１又は第２の光搬送波を除去後に電気信号に変換する光受信装置とを含む光通信システムが記載されている。また、特許文献２には、光伝送路から入力される受信信号の弁別閾値を決定する方法が記載されている。 As a technique related to the multiplexed optical transmission apparatus, Patent Document 1 discloses an optical signal including a first sideband and a first optical carrier wave of the same polarization, and a second sideband and a second optical carrier wave. An optical communication system is described that includes an optical transmitter to generate and an optical receiver that receives an optical signal and converts it to an electrical signal after removing the first or second optical carrier. Patent Document 2 describes a method for determining a discrimination threshold of a received signal input from an optical transmission line.
特開２０１０－２１２８３５号公報JP 2010-212835 A 特開２００２－９６９９号公報JP 2002-9699 A
　上記の多重光伝送装置では、波長多重により信号を多重していた。しかしながら、多重できる信号は、スペクトラムの幅で決まっているため、決まった波長数以上は多重できなかった。
　本発明は、このような課題を解決するためになされたものであり、関連する技術よりも多重密度を増やすことを目的とする。 In the above multiplexed optical transmission apparatus, signals are multiplexed by wavelength multiplexing. However, since signals that can be multiplexed are determined by the width of the spectrum, it was not possible to multiplex more than a predetermined number of wavelengths.
The present invention has been made to solve such a problem, and an object of the present invention is to increase the multiplexing density as compared with the related art.
　本発明に係わる典型的な多重光伝送装置は、
　それぞれ波長の異なる光を放出する複数の光源と、複数の光源にそれぞれ対応して設けられ、複数の光源からの複数の光を少なくとも二方向の偏光方向の光とする複数の偏光素子と、複数の偏光素子にそれぞれ対応して設けられ、複数の偏光素子の各々からの光と情報信号とが入力され、この光が情報信号により変調された光信号を出力する複数の光信号変調器と、複数の光信号変調器からの光信号を多重化して出力する信号多重部と、を含む光送信機と、
　光送信機から受信した光信号を波長ごとに信号分離する信号分離部と、信号分離された光信号のうち、前記少なくとも二方向の偏光方向の光のうちの一つの偏光方向の光をそれぞれ通過させる複数の偏光コントローラと、を含む受信機と、
　を備える。 A typical multiple optical transmission apparatus according to the present invention is:
A plurality of light sources that emit light having different wavelengths, a plurality of polarizing elements that are respectively provided corresponding to the plurality of light sources, and that use a plurality of light from the plurality of light sources as light in at least two polarization directions; A plurality of optical signal modulators that are provided corresponding to each of the polarizing elements, input light from each of the plurality of polarizing elements and an information signal, and output an optical signal in which the light is modulated by the information signal; An optical transmitter including a signal multiplexing unit that multiplexes and outputs optical signals from a plurality of optical signal modulators, and
A signal separation unit that separates the optical signal received from the optical transmitter for each wavelength, and the light of one of the at least two polarization directions out of the separated optical signal. A plurality of polarization controllers; and a receiver comprising:
Is provided.
　本発明に係わる典型的な光送信機は、それぞれ波長の異なる光を放出する複数の光源と、複数の光源にそれぞれ対応して設けられ、複数の光源からの複数の光を少なくとも二方向の偏光方向の光とする複数の偏光素子と、複数の偏光素子にそれぞれ対応して設けられ、複数の偏光素子の各々からの光と情報信号とが入力され、この光が情報信号により変調された光信号を出力する複数の光信号変調器と、複数の光信号変調器からの光信号を多重化して出力する信号多重部と、を備える。 A typical optical transmitter according to the present invention includes a plurality of light sources that emit light having different wavelengths, and a plurality of light sources that correspond to the plurality of light sources, respectively, and the light from the plurality of light sources is polarized in at least two directions. Light that is provided in correspondence with each of the plurality of polarizing elements, and the light from each of the plurality of polarizing elements and the information signal are input, and the light is modulated by the information signal A plurality of optical signal modulators for outputting signals, and a signal multiplexing unit for multiplexing and outputting optical signals from the plurality of optical signal modulators.
　本発明に係わる典型的な受信機は、少なくとも二方向の偏光方向に偏光された複数の波長の光が多重化された光信号を受信し、この光信号を波長ごとに信号分離する信号分離部と、信号分離された光信号のうち、前記少なくとも二方向の偏光方向の光のうちの一つの偏光方向の光をそれぞれ通過させる複数の偏光コントローラと、を備える。 A typical receiver according to the present invention receives an optical signal obtained by multiplexing light of a plurality of wavelengths polarized in at least two polarization directions, and separates the optical signal for each wavelength. And a plurality of polarization controllers that respectively pass light in one polarization direction out of the light in the polarization directions in at least two directions among the optical signals that have been signal-separated.
　本発明に係わる典型的な多重光伝送方法は、
　光送信機において、複数の光源から、それぞれ波長の異なる光を放出し、複数の光源からの複数の光を少なくとも二方向の偏光方向の光とし、偏光された光と情報信号とを用いて信号変調を行い、それぞれ信号変調された複数の光信号を多重化して送信し、
　受信機において、光送信機から受信した光信号を波長ごとに信号分離し、信号分離された光信号を前記少なくとも二方向の偏光方向の光のうちの一つの偏光方向の光とする。 A typical multiplexed optical transmission method according to the present invention is as follows.
In an optical transmitter, light having different wavelengths is emitted from a plurality of light sources, and the plurality of lights from the plurality of light sources are converted to light having at least two polarization directions, and signals are obtained using polarized light and information signals. Performs modulation, multiplexes and transmits a plurality of signal-modulated optical signals,
In the receiver, the optical signal received from the optical transmitter is separated for each wavelength, and the separated optical signal is set as light in one polarization direction among the light in the at least two polarization directions.
　本発明によれば、以下に記載するような典型的な効果を奏する。
　第１の効果は、光の偏光特性を利用することで、多重密度を増やすことができることである。
　第２の効果は、偏光の制御を行うことで、多重数に応じて偏光軸数を変えることができることである。 According to the present invention, there are typical effects as described below.
The first effect is that the multiplexing density can be increased by utilizing the polarization characteristics of light.
The second effect is that the number of polarization axes can be changed according to the number of multiplexing by controlling the polarization.
図１は、背景技術となる多重光伝送装置の構成例を示すブロック図である。FIG. 1 is a block diagram illustrating a configuration example of a multiplex optical transmission apparatus as a background art. 図２は、本発明に係わる送信機の一実施形態を示すブロック図である。FIG. 2 is a block diagram showing an embodiment of a transmitter according to the present invention. 図３は、本発明に係わる受信機の一実施形態を示すブロック図である。FIG. 3 is a block diagram showing an embodiment of a receiver according to the present invention. 図４は、波長と、偏光の配置の一配置例を示す図である。FIG. 4 is a diagram illustrating an arrangement example of the arrangement of wavelength and polarization. 図５は、本発明に係わる多重光伝送装置による多重光伝送方法を示すフローチャートである。FIG. 5 is a flowchart showing a multiplexed optical transmission method by the multiplexed optical transmission apparatus according to the present invention.
　以下、本発明の典型的な実施形態について図面を用いて詳細に説明する。 Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings.
　本発明に係わる多重光伝送装置の一実施形態は、図２に示す送信機（光送信機）と図３に示す受信機（光受信機）とを光ファイバ等の光伝送路で接続して構成される。 One embodiment of a multiplex optical transmission apparatus according to the present invention is such that the transmitter (optical transmitter) shown in FIG. 2 and the receiver (optical receiver) shown in FIG. 3 are connected by an optical transmission line such as an optical fiber. Composed.
　図２に示す送信機は、レーザーダイオード（LD）１１，１１１と、偏光フィルタ１２，１１２と、光信号変調器１３，１１３と、光／電気信号変換回路１４，１１４と、信号多重部１５とを備えている。 The transmitter shown in FIG. 2 includes laser diodes (LDs) 11 and 111, polarization filters 12 and 112, optical signal modulators 13 and 113, optical / electrical signal conversion circuits 14 and 114, and a signal multiplexing unit 15. It has.
　レーザーダイオード１１，１１１は、それぞれ波長の異なる光を放出する光源である。本実施形態では、レーザーダイオード１１が特定波長λ1の光信号（CW光）を出力し、レーザーダイオード１１１が波長λ1とは異なる特定波長λ2の光信号（CW光）を出力する。
　偏光フィルタ１２，１１２は、レーザーダイオード１１，１１１にそれぞれ対応して設けられ、レーザーダイオード１１，１１１からの光信号を少なくとも二方向の偏光方向の光信号とする偏光素子である。偏光フィルタ１２の偏光方向は、偏光フィルタ１１２の偏光方向と異なっている。本実施形態では、偏光フィルタ１２が入力光をｙ方向の偏光特性（ｙ偏光）をもつ光に変換し、偏光フィルタ１１２が入力光をｘ方向の偏光特性（ｘ偏光）をもつ光に変換する。 The laser diodes 11 and 111 are light sources that emit light having different wavelengths. In this embodiment, the laser diode 11 outputs an optical signal (CW light) having a specific wavelength λ1, and the laser diode 111 outputs an optical signal (CW light) having a specific wavelength λ2 different from the wavelength λ1.
The polarization filters 12 and 112 are polarization elements that are provided corresponding to the laser diodes 11 and 111, respectively, and convert the optical signals from the laser diodes 11 and 111 into optical signals having at least two polarization directions. The polarization direction of the polarization filter 12 is different from the polarization direction of the polarization filter 112. In this embodiment, the polarization filter 12 converts input light into light having a polarization characteristic in the y direction (y polarization), and the polarization filter 112 converts input light into light having a polarization characteristic in the x direction (x polarization). .
　光／電気信号変換回路１４，１１４は、送信機に入力された光信号を電気信号に変換する光電変換器である。変換された電気信号を情報信号と呼ぶ。
　光信号変調器１３，１１３は、偏光フィルタ１２，１１２にそれぞれ対応して設けられ、偏光フィルタ１２，１１２の各々からの光信号と光／電気信号変換回路１４，１１４の各々からの情報信号とが入力され、光信号が情報信号により変調された光変調信号を出力する。本実施形態では、光信号変調器１３がｙ偏光特性をもつ光変調信号を出力し、光信号変調器１１３がｘ偏光特性をもつ光変調信号を出力する。
　信号多重部１５は、光信号変調器１３，１１３からの光変調信号を多重化して出力する。信号多重部１５は、例えばマルチプレクサにより構成される。 The optical / electrical signal conversion circuits 14 and 114 are photoelectric converters that convert an optical signal input to the transmitter into an electrical signal. The converted electric signal is called an information signal.
The optical signal modulators 13 and 113 are provided corresponding to the polarization filters 12 and 112, respectively, and optical signals from the polarization filters 12 and 112 and information signals from the optical / electrical signal conversion circuits 14 and 114, respectively. And an optical modulation signal obtained by modulating the optical signal with the information signal is output. In the present embodiment, the optical signal modulator 13 outputs an optical modulation signal having y polarization characteristics, and the optical signal modulator 113 outputs an optical modulation signal having x polarization characteristics.
The signal multiplexer 15 multiplexes and outputs the optical modulation signals from the optical signal modulators 13 and 113. The signal multiplexing unit 15 is configured by a multiplexer, for example.
　図３に示す受信機は、信号分離部５０と、偏光コントローラ６１，１６１と、レーザーダイオード（LD）６２，１６２と、偏光フィルタ６３，１６３と、カプラ６４，１６４と、受信機６５，１６５と、フレーム検出器６６，１６６と、エラー検出器６７，１６７と、偏光制御回路６８，１６８と、光／電気変換器６９，１６９とを備えている。 The receiver shown in FIG. 3 includes a signal separation unit 50, polarization controllers 61 and 161, laser diodes (LD) 62 and 162, polarization filters 63 and 163, couplers 64 and 164, and receivers 65 and 165. Frame detectors 66 and 166, error detectors 67 and 167, polarization control circuits 68 and 168, and optical / electrical converters 69 and 169.
　信号分離部５０は、送信機からの光信号を受信し、その光信号を波長ごとに信号分離する。送信機からは、少なくとも二方向の偏光方向に偏光された複数の波長の光が多重化された光信号が送信される。本実施形態では、ｙ偏光特性をもつ波長λ1の光変調信号と、ｘ偏光特性をもつ波長λ2の光変調信号とが多重化された光信号が送信される。信号分離部５０は、この光信号を波長ごとに分離する。信号多重部５０は、例えばデマルチプレクサにより構成される。 The signal separator 50 receives the optical signal from the transmitter and separates the optical signal for each wavelength. The transmitter transmits an optical signal in which light of a plurality of wavelengths polarized in at least two polarization directions is multiplexed. In the present embodiment, an optical signal in which an optical modulation signal having a wavelength λ1 having y-polarization characteristics and an optical modulation signal having a wavelength λ2 having x-polarization characteristics is multiplexed is transmitted. The signal separation unit 50 separates this optical signal for each wavelength. The signal multiplexing unit 50 is configured by a demultiplexer, for example.
　偏光コントローラ６１，１６１は、信号分離された光信号のうち、上述した少なくとも二方向の偏光方向の光のうちの一つの偏光方向の光をそれぞれ通過させる。偏光コントローラ６１が通過させる光の偏光方向は、偏光コントローラ１６１が通過させる光の偏光方向と異なる。本実施形態では、偏光コントローラ６１がｙ偏光特性をもつ光を通過させ、偏光コントローラ１６１がｘ偏光特性をもつ光を通過させる。 The polarization controllers 61 and 161 pass light in one polarization direction among the above-described light in at least two polarization directions from among the separated optical signals. The polarization direction of the light that the polarization controller 61 passes is different from the polarization direction of the light that the polarization controller 161 passes. In the present embodiment, the polarization controller 61 allows light having y-polarization characteristics to pass, and the polarization controller 161 allows light having x-polarization characteristics to pass.
　レーザーダイオード６２，１６２は、それぞれ送信機のレーザーダイオード１１，１１１と同じ光源である。本実施形態では、レーザーダイオード６２が特定波長λ1のローカルCW光を出力し、レーザーダイオード１６２が波長λ1とは異なる特定波長λ2のローカルCW光を出力する。
　偏光フィルタ６３，１６３は、それぞれ送信機の偏光フィルタ１２，１１２と同じ偏光素子である。 The laser diodes 62 and 162 are the same light sources as the laser diodes 11 and 111 of the transmitter, respectively. In this embodiment, the laser diode 62 outputs local CW light having a specific wavelength λ1, and the laser diode 162 outputs local CW light having a specific wavelength λ2 different from the wavelength λ1.
The polarizing filters 63 and 163 are the same polarizing elements as the polarizing filters 12 and 112 of the transmitter, respectively.
　カプラ６４，１６４は、偏光コントローラ６１，１６１の各々から入力される信号光と、偏光フィルタ６３，１６３の各々から入力されるローカルCW光とを重畳する。
　受信機６５，１６５は、コヒーレント受信により、光変調信号を復調して、電気信号からなる情報信号を得る。 The couplers 64 and 164 superimpose the signal light input from each of the polarization controllers 61 and 161 and the local CW light input from each of the polarization filters 63 and 163.
The receivers 65 and 165 demodulate the optical modulation signal by coherent reception to obtain an information signal including an electrical signal.
　フレーム検出器６６，１６６は、復調された情報信号についてフレーム検出を行う。
　エラー検出器６７，１６７は、フレーム検出の結果に基づいて、復調された情報信号のエラーを検出する。
　偏光制御回路６８，１６８は、エラー検出の結果に基づいて、情報信号のエラーが抑制されるように偏光コントローラ６１，１６１の偏光を制御する偏光制御部である。
　光／電気変換器６９，１６９は、情報信号を電気信号から光信号に変換して出力する。 Frame detectors 66 and 166 perform frame detection on the demodulated information signal.
The error detectors 67 and 167 detect an error in the demodulated information signal based on the result of frame detection.
The polarization control circuits 68 and 168 are polarization control units that control the polarization of the polarization controllers 61 and 161 so that information signal errors are suppressed based on the error detection result.
The optical / electrical converters 69 and 169 convert the information signal from an electrical signal to an optical signal and output it.
　次に、図５を参照して、本発明に係わる多重光伝送装置による多重光伝送方法について説明する。 Next, with reference to FIG. 5, a multiplexed optical transmission method by the multiplexed optical transmission apparatus according to the present invention will be described.
　図２に示す送信機において、レーザーダイオード（LD）１１の特定波長λ1の光信号が偏光フィルタ１２へ入力される（ステップＳ２１１）。偏光フィルタ１２へ入力された光信号は、ｙ方向の偏光特性（ｙ偏光）をもった光信号に変換されて、光信号変調器１３へ入力される（ステップＳ２１２）。一方、送信機へ入力された光信号は、光/電気信号変換回路１４にて電気信号に変換されて、情報信号が生成される。この情報信号も光信号変調器１３へ入力される（ステップＳ２１２）。そして、光信号変調器１３にて、偏光された光信号及び情報信号を用いて信号変調が行われ、ｙ偏光特性をもつ波長λ1の光変調信号が信号多重部１５へ入力される（ステップＳ２１３）。 2, the optical signal of the specific wavelength λ1 of the laser diode (LD) 11 is input to the polarization filter 12 (step S211). The optical signal input to the polarization filter 12 is converted into an optical signal having a polarization characteristic in the y direction (y-polarized light) and input to the optical signal modulator 13 (step S212). On the other hand, the optical signal input to the transmitter is converted into an electrical signal by the optical / electrical signal conversion circuit 14 to generate an information signal. This information signal is also input to the optical signal modulator 13 (step S212). Then, the optical signal modulator 13 performs signal modulation using the polarized optical signal and the information signal, and an optical modulation signal having a wavelength λ 1 having y polarization characteristics is input to the signal multiplexing unit 15 (step S 213). ).
　また、レーザーダイオード（LD）１１１の特定波長λ2の光信号が偏光フィルタ１１２へ入力される（ステップＳ２１１）。偏光フィルタ１１２へ入力された光信号は、ｘ方向の偏光特性（ｘ偏光）をもった光信号に変換されて、光信号変調器１１３へ入力される（ステップＳ２１２）。一方、送信機へ入力された他の光信号は、光/電気信号変換回路１１４にて電気信号に変換されて、情報信号が生成される。この情報信号も光信号変調器１１３へ入力される（ステップＳ２１２）。そして、光信号変調器１１３にて、偏光された光信号及び情報信号を用いて信号変調が行われ、ｘ偏光特性をもつ波長λ2の光変調信号が信号多重部１５へ入力される（ステップＳ２１３）。 Also, the optical signal of the specific wavelength λ2 of the laser diode (LD) 111 is input to the polarization filter 112 (step S211). The optical signal input to the polarization filter 112 is converted into an optical signal having x-direction polarization characteristics (x-polarized light) and input to the optical signal modulator 113 (step S212). On the other hand, another optical signal input to the transmitter is converted into an electrical signal by the optical / electrical signal conversion circuit 114, and an information signal is generated. This information signal is also input to the optical signal modulator 113 (step S212). Then, the optical signal modulator 113 performs signal modulation using the polarized optical signal and the information signal, and an optical modulation signal having a wavelength λ2 having x polarization characteristics is input to the signal multiplexing unit 15 (step S213). ).
　ｙ偏光特性をもった光変調信号とｘ偏光特性をもった光変調信号は、信号多重部１５にて多重化され、光伝送路を介して、受信機へ送信される（ステップＳ２１３）。 The light modulation signal having the y polarization characteristic and the light modulation signal having the x polarization characteristic are multiplexed by the signal multiplexing unit 15 and transmitted to the receiver via the optical transmission path (step S213).
　図２に示す送信機から送信された光信号は、図３に示す受信機で受信される。受信された光信号は、信号分離部５０で波長ごとに分離される（ステップＳ２１４）。 The optical signal transmitted from the transmitter shown in FIG. 2 is received by the receiver shown in FIG. The received optical signal is separated for each wavelength by the signal separation unit 50 (step S214).
　信号分離部５０で分離された波長λ1の光信号は、偏光コントローラ６１に入力され、所望の偏光（ｙ偏光）の光信号のみが偏光コントローラ６１を通過し（ステップＳ２１５）、カプラ６４へ入力される（ステップＳ２１６）。一方、レーザーダイオード（LD）６２の特定波長λ1のローカルCW光が偏光フィルタ６３へ入力され、所望の偏光（ｙ偏光）の光のみが偏光フィルタ６３を通過し、カプラ６４へ入力される（ステップＳ２１６）。カプラ６４で信号光とローカル光が重畳されることで、受信機６５でコヒーレント受信されて（ステップＳ２１７）、電気信号からなる情報信号が復調される。この情報信号は、フレーム検出器６６を経由して、後段の光/電気変換器６９で電気信号から光信号に変換され、光信号として出力される。 The optical signal of wavelength λ1 separated by the signal separation unit 50 is input to the polarization controller 61, and only the optical signal of the desired polarization (y polarization) passes through the polarization controller 61 (step S215) and is input to the coupler 64. (Step S216). On the other hand, the local CW light of the specific wavelength λ1 of the laser diode (LD) 62 is input to the polarization filter 63, and only the light having the desired polarization (y polarization) passes through the polarization filter 63 and is input to the coupler 64 (step). S216). The coupler 64 superimposes the signal light and the local light, so that the receiver 65 performs coherent reception (step S217), and the information signal including the electric signal is demodulated. This information signal is converted from an electrical signal to an optical signal by a subsequent optical / electrical converter 69 via the frame detector 66 and output as an optical signal.
　一方、情報信号は、フレーム検出器６６でフレーム検出され、続いてエラー検出器６７でエラー検出が行われる。そして、エラーが最小となるように、偏光制御回路６８により偏光コントローラ６１の偏光が制御される。 On the other hand, the information signal is subjected to frame detection by the frame detector 66, and then error detection is performed by the error detector 67. The polarization control circuit 68 controls the polarization of the polarization controller 61 so that the error is minimized.
　同様に、信号分離部５０で分離された波長λ2の光信号は、偏光コントローラ１６１に入力され、所望の偏光（ｘ偏光）の光信号のみが偏光コントローラ１６１を通過し（ステップＳ２１５）、カプラ１６４へ入力される（ステップＳ２１６）。一方、レーザーダイオード（LD）１６２の特定波長λ2のローカルCW光が偏光フィルタ１６３へ入力され、所望の偏光（ｘ偏光）の光のみが偏光フィルタ１６３を通過し、カプラ１６４へ入力される（ステップＳ２１６）。カプラ１６４で信号光とローカル光が重畳されることで、受信機１６５でコヒーレント受信されて（ステップＳ２１７）、電気信号からなる情報信号が復調される。この情報信号は、フレーム検出器１６６を経由して、後段の光/電気変換器１６９で電気信号から光信号に変換され、光信号として出力される。 Similarly, the optical signal of wavelength λ2 separated by the signal separation unit 50 is input to the polarization controller 161, and only the optical signal of desired polarization (x polarization) passes through the polarization controller 161 (step S215), and the coupler 164 (Step S216). On the other hand, the local CW light of the specific wavelength λ 2 of the laser diode (LD) 162 is input to the polarization filter 163, and only the light of the desired polarization (x polarization) passes through the polarization filter 163 and is input to the coupler 164 (step). S216). The signal light and the local light are superimposed by the coupler 164, so that coherent reception is performed by the receiver 165 (step S217), and an information signal including an electric signal is demodulated. This information signal is converted from an electrical signal to an optical signal by a subsequent optical / electrical converter 169 via a frame detector 166 and output as an optical signal.
　一方、情報信号は、フレーム検出器１６６でフレーム検出され、続いてエラー検出器１６７でエラー検出が行われる。そして、エラーが最小となるように、偏光制御回路１６８により偏光コントローラ１６１の偏光が制御される。 On the other hand, the information signal is subjected to frame detection by the frame detector 166, and then error detection is performed by the error detector 167. Then, the polarization controller 161 controls the polarization of the polarization controller 161 so that the error is minimized.
　この様にして、波長と、偏光に依存した信号光のみを受信機で受信することができる。 In this way, only the signal light depending on the wavelength and polarization can be received by the receiver.
　なお、本実施形態では、偏光方向をｘ偏光およびｙ偏光のみとしているが、偏光方向の角度間隔を細かくして３方向以上の偏光方向を用いて多重数を増やしてもよい。また、簡易化のため、波長λ1、λ2の光信号を多重化した例について説明したが、それ以上の数の波長の光信号を多重化する送信機、それらを分離する受信機を構成してもよいことは勿論である。例えば図４に示すように、送信機で波長がλ1～λ6の光信号を多重化し、受信機で多重化された信号を分離してもよい。さらに、送信機で７つ以上の波長の光信号を多重化し、受信機で多重化された信号を分離してもよい。 In this embodiment, the polarization directions are only x-polarized light and y-polarized light, but the number of multiplexing may be increased by using three or more polarization directions by narrowing the angular interval of the polarization direction. For simplicity, an example in which optical signals with wavelengths λ1 and λ2 are multiplexed has been described. However, a transmitter that multiplexes optical signals with a larger number of wavelengths and a receiver that separates them are configured. Of course, it is also good. For example, as shown in FIG. 4, an optical signal having a wavelength of λ1 to λ6 may be multiplexed by a transmitter, and the multiplexed signal may be separated by a receiver. Further, optical signals of seven or more wavelengths may be multiplexed by the transmitter, and the multiplexed signal may be separated by the receiver.
　次に、波長と偏光の配置の一配置例を、図４を参照して説明する。 Next, an example of the arrangement of wavelength and polarization will be described with reference to FIG.
　図４において、送信機が送出する信号は、（波長，偏光）＝（λ１，ｙ偏光）、（λ３，ｙ偏光）、（λ５，ｙ偏光）、（λ２，ｘ偏光）、（λ４，ｘ偏光）、（λ６，ｘ偏光）と、並んでいる。 In FIG. 4, the signals transmitted by the transmitter are (wavelength, polarization) = (λ1, y polarization), (λ3, y polarization), (λ5, y polarization), (λ2, x polarization), (λ4, x (Polarized light) and (λ6, x-polarized light).
　λ１、λ３、λ５は波長間隔が50GHzのｙ偏光、λ２、λ４、λ６は波長間隔は50GHzのｘ偏光である。そして、λ１，λ２，λ３，λ４，λ５，λ６は、２５GHｚの波長間隔で配置できる。 Λ1, λ3, and λ5 are y-polarized light with a wavelength interval of 50 GHz, and λ2, λ4, and λ6 are x-polarized light with a wavelength interval of 50 GHz. Λ1, λ2, λ3, λ4, λ5, and λ6 can be arranged at a wavelength interval of 25 GHz.
　図１に示したような背景技術であれば、波長間隔は50GHzの信号密度しかとれない場合でも、偏光を利用することで、密度を２倍にすることができる。したがって、本実施形態では、長距離光伝送装置において波長多重と共に、光の偏光を利用した多重を行うことにより、多重できる信号密度を増加できる。 In the case of the background art as shown in FIG. 1, even if the wavelength interval can only take a signal density of 50 GHz, the density can be doubled by using polarized light. Therefore, in this embodiment, the signal density that can be multiplexed can be increased by performing multiplexing using wavelength polarization and polarization of light in the long-distance optical transmission apparatus.
　上記の実施形態の一部又は全部は、以下の付記のようにも記載されうるが、以下の構成には限られない。 Some or all of the above embodiments can be described as in the following supplementary notes, but are not limited to the following configurations.
（付記１）
　それぞれ波長の異なる光を放出する複数の光源と、該複数の光源に対応して設けられ、該複数の光源からの複数の光を少なくとも二方向の偏光方向の光とする複数の偏光素子と、前記複数の偏光素子に対応して設けられ、各偏光素子からの光と情報信号とがそれぞれ入力される複数の光信号変調器と、前記複数の光信号変調器からの光信号を多重化する信号多重部と、を備えた光送信機と、
　前記光送信機から受信した光信号を波長ごとに信号分離する信号分離部と、信号分離された光信号のうち、前記少なくとも二方向の偏光方向の光のうちの一つの偏光方向の光をそれぞれ通過させる複数の偏光コントローラと、を備えた受信機と、
を有する多重光伝送装置。 (Appendix 1)
A plurality of light sources that emit light having different wavelengths, a plurality of polarizing elements that are provided corresponding to the plurality of light sources, and that use the light from the plurality of light sources as light in at least two polarization directions; A plurality of optical signal modulators provided corresponding to the plurality of polarizing elements, to which light and information signals from the respective polarizing elements are respectively input, and optical signals from the plurality of optical signal modulators are multiplexed. An optical transmitter comprising: a signal multiplexing unit;
A signal separation unit that separates an optical signal received from the optical transmitter for each wavelength; and a light in one polarization direction among the light in the polarization directions in at least two directions among the optical signals that have been separated. A receiver having a plurality of polarization controllers to pass;
Multiplexed optical transmission apparatus having
（付記２）
　付記１の多重光伝送装置において、前記複数の偏光コントローラの光信号から復調された情報信号のエラーを検出するエラー検出器と、該エラーを抑制するように前記偏光コントローラの偏光を制御する偏光制御部とを有する多重光伝送装置。 (Appendix 2)
In the multiplexed optical transmission apparatus according to appendix 1, an error detector that detects an error in an information signal demodulated from the optical signals of the plurality of polarization controllers, and a polarization control that controls the polarization of the polarization controller so as to suppress the errors A multiple optical transmission device.
（付記３）
　それぞれ波長の異なる光を放出する複数の光源と、該複数の光源に対応して設けられ、該複数の光源からの複数の光を少なくとも二方向の偏光方向の光とする複数の偏光素子と、前記複数の偏光素子に対応して設けられ、各偏光素子からの光信号と情報信号とがそれぞれ入力される複数の光信号変調器と、前記複数の光信号変調器からの光信号を多重化する信号多重部と、を備えた光送信機。 (Appendix 3)
A plurality of light sources that emit light having different wavelengths, a plurality of polarizing elements that are provided corresponding to the plurality of light sources, and that use the light from the plurality of light sources as light in at least two polarization directions; A plurality of optical signal modulators provided corresponding to the plurality of polarizing elements, to which optical signals and information signals from the respective polarizing elements are respectively input, and optical signals from the plurality of optical signal modulators are multiplexed. An optical transmitter comprising: a signal multiplexing unit;
（付記４）
　少なくとも二方向の偏光方向に偏光され、複数の波長に多重化された光信号を受信し、該光信号を波長ごとに信号分離する信号分離部と、信号分離された光信号のうち、前記少なくとも二方向の偏光方向の光のうちの一つの偏光方向の光をそれぞれ通過させる複数の偏光コントローラと、を備えた受信機。 (Appendix 4)
Receiving an optical signal polarized in at least two polarization directions and multiplexed into a plurality of wavelengths, and separating the optical signal for each wavelength; and at least the optical signal among the separated optical signals A receiver comprising: a plurality of polarization controllers that respectively pass light in one polarization direction out of light in two polarization directions.
（付記５）
　付記４の受信機において、前記複数の偏光コントローラの光信号から復調された情報信号のエラーを検出するエラー検出器と、該エラーを抑制するように前記偏光コントローラの偏光を制御する偏光制御部とを有する受信機。 (Appendix 5)
In the receiver of Appendix 4, an error detector that detects an error in an information signal demodulated from the optical signals of the plurality of polarization controllers, and a polarization controller that controls the polarization of the polarization controller so as to suppress the errors, Having a receiver.
（付記６）
　光送信機において、複数の光源から、それぞれ波長の異なる光を放出し、該複数の光源からの複数の光を少なくとも二方向の偏光方向の光とし、偏光された光と情報信号とを用いて信号変調を行い、それぞれ信号変調された複数の光信号を多重化して送信し、
　受信機において、前記光送信機から受信した光信号を波長ごとに信号分離し、信号分離された光信号を前記少なくとも二方向の偏光方向の光のうちの一つの偏光方向の光とする、多重光伝送方法。 (Appendix 6)
In an optical transmitter, light having different wavelengths is emitted from a plurality of light sources, the plurality of lights from the plurality of light sources are set as light in at least two polarization directions, and the polarized light and the information signal are used. Performs signal modulation, multiplexes and transmits a plurality of optical signals each modulated,
In the receiver, the optical signal received from the optical transmitter is signal-separated for each wavelength, and the optical signal thus separated is used as light having one polarization direction out of the light having at least two polarization directions. Optical transmission method.
　この出願は、２０１１年３月２４日に出願された日本出願特願２０１１－０６５７００号を基礎とする優先権を主張し、その開示のすべてをここに取り込む。 This application claims priority based on Japanese Patent Application No. 2011-065700 filed on Mar. 24, 2011, the entire disclosure of which is incorporated herein.
　本発明は、信号を多重化して送信し、受信した多重化信号を分離して光通信を行う多重光伝送装置、送信機、受信機及び多重光伝送方法に用いられるものである。 The present invention is used for a multiplexed optical transmission apparatus, a transmitter, a receiver, and a multiplexed optical transmission method for multiplexing and transmitting signals and separating received multiplexed signals for optical communication.
　１１，１１１…レーザーダイオード（ＬＤ）、１２，１１２…偏光フィルタ、１３，１１３…光信号変調器、１４，１５…信号多重部、５０…信号分離部、６１，１６１…偏光コントローラ、６７，１６７…エラー検出器、６８，１６８…偏光制御回路。 DESCRIPTION OF SYMBOLS 11, 111 ... Laser diode (LD) 12, 112 ... Polarization filter, 13, 113 ... Optical signal modulator, 14, 15 ... Signal multiplexing part, 50 ... Signal separation part, 61, 161 ... Polarization controller, 67, 167 ... error detector, 68, 168 ... polarization control circuit.

Claims (6)

  1. 　それぞれ波長の異なる光を放出する複数の光源と、前記複数の光源にそれぞれ対応して設けられ、前記複数の光源からの複数の光を少なくとも二方向の偏光方向の光とする複数の偏光素子と、前記複数の偏光素子にそれぞれ対応して設けられ、前記複数の偏光素子の各々からの光と情報信号とが入力され、前記光が前記情報信号により変調された光信号を出力する複数の光信号変調器と、前記複数の光信号変調器からの光信号を多重化して出力する信号多重部と、を含む光送信機と、
    　前記光送信機から受信した光信号を波長ごとに信号分離する信号分離部と、信号分離された光信号のうち、前記少なくとも二方向の偏光方向の光のうちの一つの偏光方向の光をそれぞれ通過させる複数の偏光コントローラと、を含む受信機と、
    　を備える多重光伝送装置。     A plurality of light sources that emit light having different wavelengths, and a plurality of polarizing elements that are provided corresponding to the plurality of light sources, respectively, and that use the light from the plurality of light sources as light in at least two directions of polarization. A plurality of lights provided corresponding to each of the plurality of polarizing elements, receiving light from each of the plurality of polarizing elements and an information signal, and outputting an optical signal in which the light is modulated by the information signal An optical transmitter including a signal modulator, and a signal multiplexing unit that multiplexes and outputs optical signals from the plurality of optical signal modulators;
    A signal separation unit that separates an optical signal received from the optical transmitter for each wavelength; and a light in one polarization direction among the light in the polarization directions in at least two directions among the optical signals that have been separated. A plurality of polarization controllers for passing; and a receiver comprising:
    A multiplex optical transmission device comprising:
  2. 　請求項１に記載の多重光伝送装置において、
    　前記受信機は、前記複数の偏光コントローラの光信号から復調された情報信号のエラーを検出するエラー検出器と、前記エラーが抑制されるように前記偏光コントローラの偏光を制御する偏光制御部と、をさらに含む多重光伝送装置。     The multiplex optical transmission apparatus according to claim 1,
    The receiver includes an error detector that detects an error of an information signal demodulated from an optical signal of the plurality of polarization controllers, a polarization controller that controls polarization of the polarization controller so that the error is suppressed, A multiplex optical transmission apparatus further comprising:
  3. 　それぞれ波長の異なる光を放出する複数の光源と、前記複数の光源にそれぞれ対応して設けられ、前記複数の光源からの複数の光を少なくとも二方向の偏光方向の光とする複数の偏光素子と、前記複数の偏光素子にそれぞれ対応して設けられ、前記複数の偏光素子の各々からの光と情報信号とが入力され、前記光が前記情報信号により変調された光信号を出力する複数の光信号変調器と、前記複数の光信号変調器からの光信号を多重化して出力する信号多重部と、を備える光送信機。 A plurality of light sources that emit light having different wavelengths, and a plurality of polarizing elements that are provided corresponding to the plurality of light sources, respectively, and that use the light from the plurality of light sources as light in at least two directions of polarization. A plurality of lights provided corresponding to each of the plurality of polarizing elements, receiving light from each of the plurality of polarizing elements and an information signal, and outputting an optical signal in which the light is modulated by the information signal An optical transmitter comprising: a signal modulator; and a signal multiplexing unit that multiplexes and outputs optical signals from the plurality of optical signal modulators.
  4. 　少なくとも二方向の偏光方向に偏光された複数の波長の光が多重化された光信号を受信し、前記光信号を波長ごとに信号分離する信号分離部と、信号分離された光信号のうち、前記少なくとも二方向の偏光方向の光のうちの一つの偏光方向の光をそれぞれ通過させる複数の偏光コントローラと、を備える受信機。 Receiving a light signal obtained by multiplexing light of a plurality of wavelengths polarized in at least two polarization directions, and separating the light signal for each wavelength; and among the separated light signals, A receiver comprising: a plurality of polarization controllers each passing light in one polarization direction out of the light in at least two polarization directions;
  5. 　請求項４に記載の受信機において、
    　前記複数の偏光コントローラの光信号から復調された情報信号のエラーを検出するエラー検出器と、前記エラーが抑制されるように前記偏光コントローラの偏光を制御する偏光制御部と、をさらに備える受信機。     The receiver according to claim 4, wherein
    An error detector that detects an error of an information signal demodulated from the optical signals of the plurality of polarization controllers, and a polarization controller that controls the polarization of the polarization controller so that the error is suppressed. .
  6. 　光送信機において、複数の光源から、それぞれ波長の異なる光を放出し、前記複数の光源からの複数の光を少なくとも二方向の偏光方向の光とし、偏光された光と情報信号とを用いて信号変調を行い、それぞれ信号変調された複数の光信号を多重化して送信し、
    　受信機において、前記光送信機から受信した光信号を波長ごとに信号分離し、信号分離された光信号を前記少なくとも二方向の偏光方向の光のうちの一つの偏光方向の光とする、多重光伝送方法。     In an optical transmitter, light having different wavelengths is emitted from a plurality of light sources, the plurality of lights from the plurality of light sources are set as light having at least two polarization directions, and the polarized light and the information signal are used. Performs signal modulation, multiplexes and transmits a plurality of optical signals each modulated,
    In the receiver, the optical signal received from the optical transmitter is signal-separated for each wavelength, and the optical signal thus separated is used as light having one polarization direction out of the light having at least two polarization directions. Optical transmission method.
PCT/JP2012/057145 2011-03-24 2012-03-21 Multiplexed light transmitter, transmitter, receiver, and multiplexed light transmission method WO2012128279A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0818536A (en) * 1994-06-30 1996-01-19 Hitachi Ltd Optical wavelength multiplex transmission system
JP2009060461A (en) * 2007-08-31 2009-03-19 Fujitsu Ltd Polarization multiplex transmitter
JP2009296183A (en) * 2008-06-04 2009-12-17 National Institute Of Information & Communication Technology Data transmission system and method

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0818536A (en) * 1994-06-30 1996-01-19 Hitachi Ltd Optical wavelength multiplex transmission system
JP2009060461A (en) * 2007-08-31 2009-03-19 Fujitsu Ltd Polarization multiplex transmitter
JP2009296183A (en) * 2008-06-04 2009-12-17 National Institute Of Information & Communication Technology Data transmission system and method

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