WO2016009638A1 - Dispositif de transmission optique, et procédé de transmission optique - Google Patents

Dispositif de transmission optique, et procédé de transmission optique Download PDF

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Publication number
WO2016009638A1
WO2016009638A1 PCT/JP2015/003535 JP2015003535W WO2016009638A1 WO 2016009638 A1 WO2016009638 A1 WO 2016009638A1 JP 2015003535 W JP2015003535 W JP 2015003535W WO 2016009638 A1 WO2016009638 A1 WO 2016009638A1
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Prior art keywords
light
optical transmission
optical
signal light
power
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PCT/JP2015/003535
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English (en)
Japanese (ja)
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喜久 稲田
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日本電気株式会社
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Publication of WO2016009638A1 publication Critical patent/WO2016009638A1/fr

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    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/35—Non-linear optics
    • 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
    • H04B10/25—Arrangements specific to fibre transmission
    • H04B10/2507—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion
    • 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
    • H04B10/29—Repeaters
    • H04B10/291—Repeaters in which processing or amplification is carried out without conversion of the main signal from optical form
    • H04B10/293—Signal power control

Definitions

  • the present invention relates to an optical transmission device and an optical transmission method.
  • the present invention particularly relates to an optical transmission device and an optical transmission method used in an optical transmission system in which signal light is distributed and amplified in an optical transmission line.
  • FIG. 11 is a diagram illustrating an example of the relationship between the wavelength of excitation light and the Raman gain spectrum in Raman amplification. Stimulated emission based on Raman scattering occurs due to the strong excitation light incident on the optical fiber.
  • Raman amplification is a phenomenon in which a light amplification effect is obtained in a wavelength range longer by about 100 nm than the wavelength of excitation light.
  • the amplification characteristic of signal light by Raman amplification varies depending on the power and wavelength of pump light and the power and wavelength of signal light.
  • Distributed Raman amplification causes Raman amplification to occur in an optical fiber that is an optical transmission line, and its low noise and low nonlinearity are expected to improve the transmission quality of optical transmission systems and increase the transmission span.
  • Patent Document 1 describes a transmission loss measuring apparatus using an OTDR (optical time domain reflexometer). Further, Patent Document 2 describes a power adjustment device in which the output power of a relay amplifier is adjusted by Raman gain efficiency obtained from the amount of change in noise light power.
  • OTDR optical time domain reflexometer
  • JP 2006-287649 A (paragraph [0048], FIG. 1)
  • the optical transmitter transmits a high output signal light and obtains a high Raman gain by a high output pump light source.
  • a high Raman amplification gain can be obtained, but when the signal light power in the optical fiber is very high, it is caused by the nonlinear optical effect of the optical fiber. This is because the signal light is distorted and the transmission quality of the signal light is deteriorated.
  • FIG. 12 is a diagram showing an example of a change in optical power when the number of wavelengths of WDM (wavelength division multiplexing) signal light changes in an optical transmission system using distributed Raman amplification.
  • a plurality of signal lights having different wavelengths are wavelength-multiplexed with the WDM signal light.
  • the power of the WDM signal light is not sufficiently small with respect to the power of the excitation light, a saturation phenomenon of Raman amplification occurs.
  • the Raman gain changes according to a change in the number of wavelengths of the WDM signal light (that is, a change in the power of the WDM signal light incident on the optical fiber). For example, when the number of wavelengths of WDM signal light decreases, the Raman gain increases.
  • the signal power per wavelength of the WDM signal light in the optical fiber increases from before the decrease in the number of wavelengths (“normal time” in FIG. 12).
  • the transmission quality may deteriorate due to the nonlinear optical effect.
  • An object of this invention is to provide the technique for implement
  • the first optical transmission apparatus includes an optical amplifying unit that amplifies input signal light, an excitation unit that outputs pumping light that causes distributed Raman amplification in an optical transmission line, and an optical amplification unit that amplifies the optical signal.
  • the signal light and the pumping light are combined and sent to the optical transmission line, and the light is generated by scattering of the propagation light propagating through the optical transmission line.
  • the first optical transmission method of the present invention amplifies input signal light, outputs pumping light that causes distributed Raman amplification in the optical transmission line, and combines the amplified signal light and the pumping light. Detecting the scattered light generated by the scattering in the optical transmission path of the propagating light propagating through the optical transmission path and transmitted to the optical transmission path. The power is measured, and the output power of the pumping light and the output power of the optical amplification means are controlled based on the maximum power.
  • the present invention has the effect of suppressing the deterioration of transmission quality due to the nonlinear optical effect and expanding the transmission span.
  • FIG. 1 is a block diagram illustrating a configuration of an optical transmission system 10 according to a first embodiment of this invention.
  • the optical communication system 10 includes an optical transmission device 100, an optical reception device 110, and an optical fiber 7.
  • the optical transmission device 100 outputs signal light to the optical fiber 7.
  • the optical receiver 110 receives the signal light propagated through the optical fiber 7.
  • the optical transmission apparatus 100 includes n (n is a natural number) optical transmitters 11-1n, an optical multiplexer 1, an optical amplifier 2, an excitation light source 3, an OTDR (optical time domain domain reflectometer) 4, an optical multiplexer 5, and a control circuit. 6 is provided.
  • the optical transmitters 11-1n output signal lights having different wavelengths.
  • the optical multiplexer 1 wavelength-multiplexes the signal light output from the optical transmitter 11-1n to generate WDM (wavelength-division-multiplexing) signal light.
  • the optical amplifier 2 amplifies the WDM signal light and outputs it to the optical multiplexer 5.
  • the pumping light source 3 outputs pumping light for generating distributed Raman amplification in the optical fiber 7 to the optical multiplexer 5.
  • OTDR4 is an optical pulse tester.
  • the OTDR 4 detects Rayleigh scattered light generated in the optical fiber 7 by the transmitted optical pulse test light (hereinafter referred to as “OTDR light”).
  • the optical fiber 7 is an optical transmission line on which distributed Raman amplification is performed.
  • the optical multiplexer 5 combines the WDM signal light, the excitation light, and the OTDR light, and sends these lights to the optical fiber 7. Further, the optical multiplexer 5 receives light (hereinafter referred to as “scattered light”) obtained by scattering the OTDR light in the optical fiber 7 and outputs the light to the OTDR 4.
  • the OTDR 4 receives the scattered light and obtains the power distribution of the OTDR light in the length direction of the optical fiber 7 (hereinafter referred to as “OTDR waveform”).
  • the control circuit 6 analyzes the OTDR waveform and controls the output power of the optical amplifier 2 and the excitation light source 3 based on the analysis result.
  • the WDM signal light transmitted to the optical transmission line 7 is received by the optical receiver 110.
  • the optical transmission device 100 may further include a CPU (central processing unit) 91 and a memory 92.
  • the memory 92 is a fixed, non-temporary recording medium composed of, for example, a nonvolatile semiconductor memory. However, the configuration of the memory 92 is not limited to these.
  • the memory 92 stores a program executed by the CPU 91.
  • the CPU 91 may realize the function of the optical transmission device 100 by executing a program stored in the memory 92.
  • the optical transmission apparatus 100 of the first embodiment will be described.
  • the WDM signal light and the pumping light are simultaneously transmitted from the optical transmission apparatus 100 to the optical fiber 7.
  • the WDM signal light is amplified by distributed Raman amplification generated by the pumping light.
  • An example of the relationship between the wavelength of the excitation light and the Raman gain spectrum has already been described with reference to FIG.
  • distributed Raman amplification optical amplification is distributed in the optical fiber 7 that is an amplification medium.
  • FIG. 2 is a diagram showing an example of the power distribution of the WDM signal light in the optical fiber 7 when distributed Raman amplification is used.
  • the output unit of the optical transmission apparatus 100 is described as “transmission end” in FIG.
  • the transmission end is a port on the multiplexing side (optical fiber 7 side) of the optical multiplexer 5 and is a connection portion between the optical transmission device 100 and the optical fiber 7.
  • the power of the WDM signal light is highest at the output section of the optical transmission apparatus 100.
  • the power of the WDM signal light is attenuated along with the propagation of the WDM signal light due to the loss of the optical fiber 7. This is indicated by a broken line in FIG. 2 as “when the excitation light source is OFF”. Therefore, when distributed Raman amplification is not used, in order to reduce the influence of the nonlinear optical effect, which is one of the main causes of signal quality degradation in the optical transmission system 10, a signal is output from the output unit of the optical transmission apparatus 100. It is sufficient to manage the transmission level of light to the optical transmission line.
  • the WDM signal light is amplified in a distributed manner in the optical fiber 7.
  • the power of the WDM signal light is not necessarily the maximum at the output unit of the optical transmission apparatus 100 (the port on the output side of the optical multiplexer 5 in FIG. 1), but is the maximum in the middle of transmission through the optical fiber 7.
  • a solid line in FIG. 2 as “when the excitation light source is ON”.
  • the optical transmission apparatus 100 sends out OTDR light to the optical fiber 7 in addition to the WDM signal light and the pumping light for Raman amplification.
  • the OTDR light is used to monitor the level change in the optical fiber 7 of the distributed Raman amplified signal light.
  • FIG. 3 and 4 are diagrams illustrating examples of wavelength arrangements of the pump light, the WDM signal light, and the OTDR light in the optical transmission apparatus 100.
  • FIG. The OTDR light is used to indirectly monitor the power distribution of the WDM signal light in the longitudinal direction of the optical fiber 7. For this reason, the wavelength of the OTDR light is arranged in a wavelength band where a distributed Raman amplification characteristic substantially similar to that of the WDM signal light can be obtained.
  • the wavelength of the OTDR light is slightly longer than the upper limit wavelength of the wavelength band of the WDM signal light.
  • the wavelength of the OTDR light is slightly shorter than the lower limit wavelength of the wavelength band of the WDM signal light.
  • the wavelength of the OTDR light is preferably set to a wavelength at which the distributed Raman amplification characteristic for the OTDR light is substantially the same as the distributed Raman amplification characteristic for the WDM signal light.
  • the wavelength of the OTDR light is a wavelength that can estimate the characteristic of the distributed Raman amplification for the WDM signal light based on the characteristic of the distributed Raman amplification for the OTDR light.
  • the wavelength of OTDR light is in the vicinity of the wavelength band of WDM signal light.
  • FIG. 5 is a diagram for explaining the operation of the optical transmission apparatus 100. Similar to the WDM signal light, the OTDR light is also lost by the optical fiber 7 and amplified by the pumping light. The OTDR 4 measures the OTDR waveform by receiving the OTDR light that returns to the optical transmission apparatus 100 due to Rayleigh scattering in the optical fiber 7. The OTDR waveform indicates the power distribution in the transmission direction of the OTDR light in the optical fiber 7.
  • the control circuit 6 analyzes the OTDR waveform generated by the OTDR 4 and controls the optical amplifier 2 and the pumping light source 3 so that the maximum power of the WDM signal light in the optical fiber 7 obtained from the OTDR waveform does not exceed a predetermined threshold. Controls output power.
  • the predetermined threshold is determined based on an allowable amount of transmission quality degradation caused by the nonlinear optical effect on the WDM signal light generated in the optical fiber 7. Since the wavelength of the OTDR light is in the vicinity of the WDM signal light, it is easy to estimate the power distribution of the WDM signal light from the OTDR waveform. For example, it may be estimated that the OTDR waveform is similar to the power distribution of the WDM signal light.
  • the difference in power between the OTDR light and the WDM signal light can be corrected, for example, by measuring the power of both at the transmission end.
  • the power distribution of the WDM signal light can be easily estimated from the OTDR waveform by keeping the ratio of the incident power of the OTDR light to the optical transmission line 7 and the power per wavelength of the WDM signal light constant.
  • a difference between an OTDR waveform by OTDR light having the same wavelength as the WDM signal light and an OTDR waveform by OTDR light having a wavelength near the WDM signal light may be acquired.
  • the power distribution of the WDM signal light can be estimated more accurately by correcting the OTDR waveform of the OTDR light having a wavelength in the vicinity of the WDM signal light with the difference acquired at the time of manufacture.
  • FIG. 6 is a flowchart illustrating an example of an operation procedure of the optical transmission device 100 according to the first embodiment.
  • the optical amplifier 2 amplifies the input WDM signal light (step S1 in FIG. 6), and the pumping light source 3 outputs pumping light for causing Raman amplification in the optical fiber 7 (step S2).
  • Step S1 and step S2 may be executed in the reverse order, or may be executed simultaneously.
  • the optical multiplexer 5 combines the amplified WDM signal light, the excitation light, and the OTDR light (step S3).
  • the OTDR 4 measures the power distribution in the optical fiber 7 of the OTDR light transmitted to the optical fiber 7 (step S4).
  • the control circuit 6 controls the output power of the pumping light source 3 and the output power of the optical amplifier 2 based on the power distribution measured by the OTDR 4 (Step S5).
  • the optical transmission device 100 monitors the level change in the transmission direction of the optical transmission line using OTDR light, and controls the optical amplifier 2 and the pumping light source 3 based on the monitoring result.
  • the control circuit 6 controls the output power of the optical amplifier 2 in order to change the power at the transmission end of the WDM signal light.
  • the control circuit 6 controls the output power of the excitation light source 3 in order to control the gain of Raman amplification.
  • Specific control contents for the optical amplifier 2 and the excitation light source 3 corresponding to the OTDR waveform input from the OTDR 4 may be set in the control circuit 6 in advance according to the characteristics of the OTDR waveform.
  • the optical transmission device 100 propagates the OTDR light together with the WDM signal light, and monitors the optical power change in the longitudinal direction of the optical fiber 7 of the OTDR light by the OTDR waveform, thereby indirectly monitoring the power distribution of the WDM signal light. it can. As a result, the optical transmission device 100 can control the output power of the optical amplifier 2 and the pumping light source 3 so that the maximum power of the WDM signal light in the optical fiber 7 does not exceed the threshold at which the influence of nonlinear waveform distortion occurs.
  • the optical transmission device 100 manages the maximum power of the WDM signal light in the transmission direction of the optical fiber 7 by such control, thereby suppressing the deterioration of the transmission quality of the signal light due to the nonlinear optical effect in the optical transmission path.
  • the transmission span can be expanded.
  • the optical transmission device 100 can monitor the power change per wavelength of the WDM signal light by monitoring the OTDR waveform even when the number of wavelengths of the WDM signal light changes. Therefore, the optical transmission device 100 controls the output power of the optical amplifier 2 and the excitation light source 3 based on the power change per wavelength of the WDM signal light, thereby suppressing the level fluctuation for each wavelength of the WDM signal light, The transmission quality of WDM signal light can be maintained.
  • the optical transmission apparatus 100 compensates for the power of the WDM signal light that has decreased due to the increase in the loss of the optical fiber by monitoring the change in the optical power per wavelength of the WDM signal light.
  • the output power of the optical amplifier 2 and the pumping light source 3 can be controlled. That is, the optical transmission device 100 can maintain the optical power per wavelength of the WDM signal light and maintain the transmission quality of the WDM signal light even when the loss of the optical fiber increases.
  • the optical transmission device includes an optical amplifier, an excitation light source, a measurement unit, an optical multiplexer, and a control circuit.
  • the optical amplifier amplifies the input signal light.
  • the pumping light source outputs pumping light that causes distributed Raman amplification in the optical transmission line.
  • the optical multiplexer combines the signal light amplified by the optical amplifier and the pumping light, and sends them to the optical transmission line.
  • the measurement unit measures the maximum power in the optical transmission line of the propagation light by detecting the scattered light generated by the scattering in the optical transmission line of the propagation light propagating through the optical transmission line.
  • the measurement unit notifies the control circuit of the maximum power of the measured propagation light.
  • the control circuit controls the output power of the pumping light and the output power of the optical amplifier based on the maximum power of the propagating light notified from the measurement unit.
  • the optical amplifier, pumping light source, measurement unit, optical multiplexer, and control circuit included in the optical transmission device according to the modification of the first embodiment are the optical amplifier 2, pumping light source included in the optical transmission device 100 illustrated in FIG. 3, OTDR 4, optical multiplexer 5, and control circuit 6.
  • the function of the measurement unit is not limited to the function of OTDR4.
  • the measurement unit only needs to have a function of measuring the maximum power of the propagation light in the optical transmission path by detecting scattered light and notifying the control circuit.
  • the optical transmission device of this modification having such a configuration is configured so that the maximum power of the light propagating in the optical transmission path does not exceed the threshold at which the influence of nonlinear waveform distortion occurs, and the output power of the optical amplifier and the pumping light source. Can be controlled. That is, by managing the maximum power inside the optical transmission line, the optical transmission device according to the modification of the first embodiment suppresses the deterioration of the transmission quality of the signal light due to the nonlinear optical effect in the optical transmission line.
  • the transmission span can be expanded.
  • FIG. 7 is a block diagram illustrating a configuration of the optical transmission system 20 according to the second embodiment.
  • FIG. 8 is a diagram illustrating an example of wavelength arrangement in the second embodiment.
  • the optical transmission system 20 according to the second embodiment includes an optical transmission device 200, an optical fiber 7, and an optical reception device 110.
  • the functions of the optical fiber 7 and the optical receiver 110 are the same as those in the first embodiment shown in FIG.
  • the optical transmission device 200 is different from the optical transmission device 100 according to the first embodiment in that the excitation light source 31 includes two light sources (LD1 and LD2). LD1 and LD2 are laser diodes, and the wavelength of LD1 is different from the wavelength of LD2 as shown in FIG.
  • the configuration and operation of the optical transmission device 200 other than the pumping light source 3 are basically the same as those of the optical transmission device 100.
  • the control circuit 6 independently controls the output power of the two LDs (LD1 and LD2) provided in the excitation light source 3 based on the OTDR waveform. Due to the excitation light source 3 having a plurality of wavelengths, the optical transmission device 200 has a wider Raman amplification band than the optical transmission device 100.
  • the OTDR light may be arranged one wavelength each on the short wavelength side and the long wavelength side of the WDM signal light.
  • the wavelengths of the OTDR light are indicated by upward arrows in FIG. 8 as OTDR wavelength 1 and OTDR wavelength 2.
  • the OTDR 4 outputs a plurality of OTDR lights having different wavelengths.
  • the wavelengths of two OTDR lights among the plurality of OTDR lights are near the upper limit and the lower limit of the wavelength of the WDM signal light, respectively.
  • a level difference between wavelengths of WDM signal light subjected to distributed Raman amplification in the optical fiber 7 (that is, wavelength dependence of distributed Raman gain). Can be estimated.
  • the control circuit 6 may obtain the power of each wavelength of the WDM signal light by interpolating the wavelength characteristics of the OTDR light 1 and the OTDR light 2.
  • the control circuit 6 may independently control the output power of the two LDs (LD1 and LD2) provided in the pumping light source 3 based on the comparison result of the respective OTDR waveforms by the OTDR light of two wavelengths.
  • the optical transmission device 200 suppresses the occurrence of optical power deviation between the wavelengths of the WDM signal light in the optical fiber 7, and the wavelength of the WDM signal light is reduced. There is an effect that a certain transmission quality can be secured over the entire area.
  • 7 and 8 show the case where both the excitation light source 3 and the OTDR light have two wavelengths.
  • the number of wavelengths of the excitation light source and the OTDR light is not limited to two wavelengths. Further, the number of wavelengths of the excitation light source and the number of wavelengths of the OTDR light may not be the same.
  • FIG. 9 is a block diagram illustrating a configuration of an optical transmission system 30 according to the third embodiment of this invention.
  • the optical transmission system 30 according to the third embodiment includes an optical transmission device 300, an optical fiber 7, and an optical reception device 110.
  • the functions of the optical fiber 7 and the optical receiver 110 are the same as those in the first embodiment shown in FIG.
  • the optical transmission device 300 is different from the optical transmission device 100 according to the first embodiment in that a dispersion compensation unit 8 is provided between the optical multiplexer 1 and the optical amplifier 2.
  • the configuration and operation of the optical transmission device 300 other than the control of the dispersion compensation unit 8 and the dispersion compensation unit 8 in the control circuit 6 are the same as those of the optical transmission device 100.
  • the dispersion compensator 8 imparts WDM signal light with an amount of chromatic dispersion that cancels out the chromatic dispersion caused by the optical fiber 7 at a point where the power of the WDM signal light propagating through the optical fiber 7 is maximum.
  • the dispersion compensator 8 adds the WDM signal light to the WDM signal light.
  • the dispersion compensation amount is given by ⁇ D ⁇ L1.
  • the distance L1 can be known from the OTDR waveform.
  • the optical transmission apparatus 300 according to the third embodiment having such a configuration has an effect of suppressing a decrease in transmission quality due to wavelength dispersion of the optical fiber 7 in addition to the effect of the first embodiment.
  • FIG. 10 is a block diagram showing the configuration of the optical transmission system 40 according to the fourth embodiment of the present invention.
  • the optical transmission system 40 according to the fourth embodiment includes an optical transmission device 400, an optical fiber 7, and an optical reception device 110.
  • the functions of the optical fiber 7 and the optical receiver 110 are the same as those in the first embodiment shown in FIG.
  • the optical transmission device 400 is different from the optical transmission device 100 of the first embodiment in that the control circuit 6 further controls the optical transmitter 11-1n.
  • the configuration and operation of other parts of the optical transmission device 400 are the same as those of the optical transmission device 100.
  • the control circuit 6 controls the transmission waveform of the optical transmitter 11-1n so that dispersion and waveform distortion caused by the optical fiber 7 are compensated.
  • These dispersion compensation and waveform distortion compensation in the optical transmission apparatus 400 may be either optical compensation or electrical compensation.
  • the optical transmission apparatus 400 may further include the dispersion compensator 8 described in the third embodiment between the optical multiplexer 1 and the optical amplifier 2.
  • the optical transmission apparatus 400 according to the fourth embodiment having such a configuration has an effect of suppressing a reduction in transmission quality due to chromatic dispersion and waveform distortion in addition to the effects of the first embodiment.
  • Optical amplification means for amplifying the input signal light; Pumping means for outputting pumping light that causes distributed Raman amplification in the optical transmission line; First optical multiplexing means for multiplexing the signal light amplified by the optical amplification means and the pumping light and sending them to the optical transmission line; Measuring means for measuring the maximum power of the propagation light in the optical transmission line by detecting scattered light generated by scattering of the propagation light propagating in the optical transmission line; Control means for controlling the output power of the pumping light and the output power of the optical amplifying means based on the maximum power notified from the measuring means;
  • An optical transmission device comprising:
  • the first optical multiplexing means further combines test light and sends it to the optical transmission line,
  • the measurement means outputs the test light to the first multiplexing means, and measures the maximum power by detecting the test light scattered in the optical transmission path as the scattered light.
  • the optical transmission device according to attachment 1.
  • Appendix 3 The optical transmission apparatus according to appendix 2, wherein the measuring means is an OTDR (optical time domain reflectometer).
  • the control means is configured so that the maximum power does not exceed a threshold value determined based on an allowable amount of deterioration in transmission quality of the signal light due to a nonlinear optical effect in the optical transmission path with respect to the signal light.
  • the optical transmission device according to any one of appendices 1 to 4, wherein the output power of the optical amplifying means is controlled.
  • Appendix 6 The light according to any one of appendices 2 to 5, wherein the wavelength of the test light is a wavelength capable of estimating the characteristic of the distributed Raman amplification with respect to the signal light based on the characteristic of the distributed Raman amplification with respect to the test light.
  • Transmission equipment The wavelength of the test light is a wavelength capable of estimating the characteristic of the distributed Raman amplification with respect to the signal light based on the characteristic of the distributed Raman amplification with respect to the test light.
  • Appendix 7 The optical transmission device according to any one of appendices 2 to 6, wherein the wavelength of the test light is in the vicinity of the wavelength of the signal light.
  • the test means outputs a plurality of the test lights having different wavelengths, and the wavelengths of the two test lights out of the plurality of test lights are in the vicinity of the upper limit and the lower limit of the wavelength multiplexed light, respectively.
  • the optical transmission apparatus according to appendix 8.
  • (Appendix 10) Further comprising dispersion compensation means connected to the input side of the amplification means, The test means measures the distance from the input end of the propagation light of the optical transmission path to a point where the power of the propagation light becomes the maximum power, and notifies the control means, the control means, The light according to any one of appendices 1 to 9, wherein the dispersion compensation unit is controlled based on a distance so as to give the signal light an amount of dispersion that cancels out the amount of dispersion of the optical transmission line generated at the point. Transmission equipment.
  • the excitation unit outputs a plurality of the excitation lights having different wavelengths, and the control unit is configured to output the plurality of excitations so that the wavelength dependence of the power distribution of the propagating light in the optical transmission path falls within a predetermined range.
  • the optical transmission device according to any one of appendices 1 to 10, wherein the light is controlled independently.
  • Appendix 12 The optical transmission apparatus according to any one of appendices 1 to 11, further comprising: an optical transmission unit connected so that the output signal light is input to the optical amplification unit.
  • Appendix 13 An optical transmitter connected so that the output signal light is input to the optical amplifier;
  • the second light is connected so that the light output from the plurality of optical transmission units having different wavelengths is combined, and the combined light output from the optical transmission unit is input to the optical amplification unit.
  • Appendix 15 The optical transmission device according to any one of appendices 1 to 14, An optical transmission path for propagating light output from the optical transmission device; An optical receiver for receiving the signal light output from the optical transmission line; An optical transmission system comprising:
  • (Appendix 16) Amplifies the input signal light, Outputs pumping light that causes distributed Raman amplification in the optical transmission line, The amplified signal light and the excitation light are combined and sent to the optical transmission line, By detecting scattered light generated by scattering in the optical transmission path of propagation light propagating through the optical transmission path, the maximum power in the optical transmission path of the signal light is measured, Controlling the output power of the pumping light and the output power of the optical amplification means based on the maximum power; Control method of optical transmission apparatus.
  • a control program for an optical transmission device for controlling the output power of pumping light that causes Raman amplification in the optical transmission line and the output power of optical amplification means that amplifies signal light and outputs it to the optical transmission line .
  • the OTDR 4 described in the first to fourth embodiments may be a coherent OTDR that uses coherent reception to detect scattered light.
  • the configuration for dispersion compensation and the configuration for waveform distortion compensation described in the third and fourth embodiments may be applied to the optical transmission device 200 of the second embodiment.
  • Optical transmission system 100 200, 300, 400
  • Optical transmission device 110 Optical reception device 1, 5
  • Optical multiplexer 2 Optical amplifier 3, 31 Excitation light source 4
  • OTDR 6 Control Circuit 7
  • Optical Fiber 8 Dispersion Compensator 11-1n
  • Optical Transmitter 91 CPU 92 memory

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  • Optical Modulation, Optical Deflection, Nonlinear Optics, Optical Demodulation, Optical Logic Elements (AREA)

Abstract

Afin de supprimer la dégradation d'une qualité de transmission due à un effet optique non linéaire, et l'augmentation d'une largeur de transmission, un dispositif de transmission optique comprend : des moyens d'amplification optique qui amplifient une lumière de signal entrée ; des moyens d'excitation qui émettent une lumière d'excitation qui génère une amplification Raman distribuée sur un trajet de transmission optique ; des premiers moyens de multiplexage optique qui multiplexent la lumière de signal amplifiée par les moyens d'amplification optique et la lumière d'excitation, et envoient la lumière ainsi obtenue au trajet de transmission optique ; des moyens de mesurage qui détectent la lumière diffusée générée par la diffusion de la lumière de propagation qui se propage via le trajet de transmission optique sur le trajet de transmission optique, ce qui permet de mesurer la puissance maximale de la lumière de propagation sur le trajet de transmission optique ; et des moyens de régulation qui régulent la puissance de sortie de la lumière d'excitation et la puissance de sortie des moyens d'amplification optique d'après la puissance maximale rapportée par les moyens de mesurage.
PCT/JP2015/003535 2014-07-18 2015-07-13 Dispositif de transmission optique, et procédé de transmission optique WO2016009638A1 (fr)

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JP2014147408 2014-07-18

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Citations (7)

* Cited by examiner, † Cited by third party
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JP2856435B2 (ja) * 1989-06-12 1999-02-10 日本電信電話株式会社 光ファイバアクティブ伝送路の安定化方法
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JP2005084041A (ja) * 2003-09-11 2005-03-31 Nippon Telegr & Teleph Corp <Ntt> 光伝送システムの伝送損失測定装置、およびその方法
JP2006279610A (ja) * 2005-03-29 2006-10-12 Fujitsu Ltd 光伝送装置
JP2006287649A (ja) * 2005-03-31 2006-10-19 Nec Corp 光伝送システムにおける光信号送出パワー調整装置及び光信号の送出パワー調整方法
WO2007111797A2 (fr) * 2006-03-23 2007-10-04 Xtera Communications, Inc. Dispositif et procede de mise en oeuvre d'un systeme de communication optique sans amplificateur
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JP2856435B2 (ja) * 1989-06-12 1999-02-10 日本電信電話株式会社 光ファイバアクティブ伝送路の安定化方法
JP2001235772A (ja) * 2000-02-22 2001-08-31 Sumitomo Electric Ind Ltd ラマン増幅制御装置および光伝送システム
JP2005084041A (ja) * 2003-09-11 2005-03-31 Nippon Telegr & Teleph Corp <Ntt> 光伝送システムの伝送損失測定装置、およびその方法
JP2006279610A (ja) * 2005-03-29 2006-10-12 Fujitsu Ltd 光伝送装置
JP2006287649A (ja) * 2005-03-31 2006-10-19 Nec Corp 光伝送システムにおける光信号送出パワー調整装置及び光信号の送出パワー調整方法
WO2007111797A2 (fr) * 2006-03-23 2007-10-04 Xtera Communications, Inc. Dispositif et procede de mise en oeuvre d'un systeme de communication optique sans amplificateur
WO2011130193A1 (fr) * 2010-04-16 2011-10-20 Alcatel-Lucent Usa Inc. Compensation de non-linéarité électronique pour systèmes de transmission optique

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