WO2007104211A1 - Wavelength division multiplexing system and residual dispersion compensating device and method thereof - Google Patents

Wavelength division multiplexing system and residual dispersion compensating device and method thereof Download PDF

Info

Publication number
WO2007104211A1
WO2007104211A1 PCT/CN2007/000090 CN2007000090W WO2007104211A1 WO 2007104211 A1 WO2007104211 A1 WO 2007104211A1 CN 2007000090 W CN2007000090 W CN 2007000090W WO 2007104211 A1 WO2007104211 A1 WO 2007104211A1
Authority
WO
WIPO (PCT)
Prior art keywords
dispersion
control device
residual
residual dispersion
channel
Prior art date
Application number
PCT/CN2007/000090
Other languages
English (en)
French (fr)
Inventor
Likun Zhang
Jiaying Wang
Original Assignee
Zte Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zte Corporation filed Critical Zte Corporation
Priority to US12/282,140 priority Critical patent/US8886050B2/en
Priority to KR1020087022201A priority patent/KR101295522B1/ko
Priority to EP07702022A priority patent/EP2007042A4/en
Publication of WO2007104211A1 publication Critical patent/WO2007104211A1/zh

Links

Classifications

    • 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
    • H04B10/25—Arrangements specific to fibre transmission
    • H04B10/2507—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion
    • H04B10/2513—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to chromatic dispersion
    • H04B10/25133—Arrangements specific to fibre transmission for the reduction or elimination of distortion or dispersion due to chromatic dispersion including a lumped electrical or optical dispersion compensator
    • 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
    • H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
    • H04B10/075—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal
    • H04B10/079—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using an in-service signal using measurements of the data signal
    • H04B10/0795—Performance monitoring; Measurement of transmission parameters
    • H04B10/07951—Monitoring or measuring chromatic dispersion or PMD
    • 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
    • H04B10/2581—Multimode transmission
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B2210/00—Indexing scheme relating to optical transmission systems
    • H04B2210/25—Distortion or dispersion compensation
    • H04B2210/252—Distortion or dispersion compensation after the transmission line, i.e. post-compensation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B2210/00—Indexing scheme relating to optical transmission systems
    • H04B2210/25—Distortion or dispersion compensation
    • H04B2210/254—Distortion or dispersion compensation before the transmission line, i.e. pre-compensation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B2210/00—Indexing scheme relating to optical transmission systems
    • H04B2210/25—Distortion or dispersion compensation
    • H04B2210/256—Distortion or dispersion compensation at the repeater, i.e. repeater compensation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0221—Power control, e.g. to keep the total optical power constant

Definitions

  • the present invention relates to a WDM (Wavelength Division Multiplexing) system and a method and an apparatus for adjusting the residual dispersion compensation thereof, and more particularly, to a wavelength division A multiplexing system and a method and apparatus for residual dispersion compensation of each channel after dispersion compensation of a multiplex section of a wavelength division multiplexed optical transmission system.
  • WDM Widelength Division Multiplexing
  • the single-channel rate of a wavelength division multiplexed optical transmission system is continuously improved (for example, the signal rate of a backbone transmission network is mostly upgraded from 2.5 Gb/s to 10 Gb/s), one of the important physical characteristics of a single-mode optical fiber as an optical transmission medium
  • the dispersion has become a major factor limiting the transmission distance of high-speed optical transmission systems.
  • the zero-dispersion wavelength is around 1310 nm, as shown by the dashed line in Fig. 1, and the wavelength division multiplexed optical transmission system usually operates in the C-band.
  • the wavelength range of C-band is 1529.16nm to 1560.61nm, and the dispersion coefficient near the transmission wavelength of 1550nm is about 17ps/nm/km.
  • OSNR optical signal-to-noise ratio
  • dispersion accumulation will reach 11000 ps / nm, much larger than the dispersion capacity of 10Gb / s laser source (such as the current 80km electro-absorption laser dispersion capacity of 1600ps / nm;), so high-speed wavelength division multiplexing optical transmission system must The actual transmission requirements can only be met after dispersion compensation.
  • the solid curve in Figure 1 is the dispersion coefficient curve of the fiber after dispersion compensation by the dispersion-compensating fiber. Obviously, it can only be near a certain central wavelength of the C-band.
  • the dispersion-compensating fiber can periodically minimize the accumulated dispersion of the fiber link.
  • the other wavelengths on both sides of the center wavelength, especially the edge wavelengths have large dispersion coefficients. After multiple spans of transmission, the residual dispersion will increase a lot.
  • high-speed wavelength division multiplexing optical transmission systems can usually perform dispersion compensation in a multiplex section or a single channel.
  • DCM Dispersion Compensating Module
  • Forward dispersion compensation mode using forward dispersion compensation
  • the module the fiber dispersion compensation module is disposed before the post-amplifier
  • Line dispersion compensation method using line dispersion compensation module (fiber dispersion compensation module is set between line optical amplifiers) for line dispersion compensation
  • backward dispersion compensation method using backward dispersion compensation module (fiber dispersion compensation module is set in front light After the amplifier) compensates for dispersion.
  • the fiber dispersion problem can be solved by the above method, so that the residual dispersion of the transmission system is within the range of the dispersion tolerance allowed by the receiver.
  • the relative dispersion slopes of common fiber and dispersion compensation modules are not necessarily the same, when the number of channels is large and the transmission distance is very long, even if the residual dispersion of one wavelength channel is completely optimized and the bit error rate is the lowest, other channels (especially The residual dispersion of the edge wavelength channel may still be large, and it is difficult to ensure that there is no error after transmission.
  • Figure 3 shows the residual dispersion of the wavelength division multiplexed optical transmission system, where D+ and D- are the allowable dispersion tolerance ranges of the receiver, and D+ma and D-max represent the cumulative positive residual dispersion and negative residual dispersion, respectively. Maximum value.
  • the dispersion-compensating fiber can only compensate for a certain central wavelength cumulative dispersion to a minimum, while other central wavelengths still have a large cumulative residual dispersion, so even if the multiplex section of the wavelength division system is chromatic. It is also difficult for the dispersion compensator to accurately compensate the dispersion of all the paths to the optimum effect, so the dispersion overcompensation and undercompensation of each path are difficult to avoid.
  • Figure 4 is a residual dispersion compensation method for a high-speed wavelength division multiplexing optical transmission system using an EDC (Electrical Dispersion Compensation) device.
  • the problem with this method is that the dispersion compensation of the electric dispersion compensation device is fixed and very limited, and can only reduce the influence of the residual dispersion of the system to a certain extent, and cannot fundamentally solve the residual dispersion problem existing in the system. It is even more difficult to dynamically adjust the dispersion compensation amount of each wavelength channel of the wavelength division multiplexing system. Due to the non-adjustability of the dispersion compensation amount, the application lacks flexibility in the actual wavelength division multiplexing optical transmission system.
  • the device uses the adjustable b dispersion compensation device to compensate the residual dispersion of the channel layer after the centralized compensation of the fiber dispersion compensation module for the multiplex section of the wavelength division multiplexing optical transmission system, optimizes the residual dispersion of each channel, and solves the long-distance optical transmission.
  • an aspect of the present invention provides a device for residual dispersion compensation of a wavelength division multiplexing system, including a performance parameter detecting device, a center control device, and a tonable dispersion compensator control device, wherein: a performance parameter detecting device a performance parameter for receiving and detecting the optical signal at the receiving end, and transmitting the detection result of the performance parameter to the central control device; the central control device is configured to determine a dispersion adjustment mode of the tunable dispersion compensator according to the detection result of the performance parameter, And sent to the tunable dispersion compensator control device through control signaling; and a tunable dispersion compensator control device, configured to receive the control command sent by the central control device and adjust the dispersion of the tunable dispersion compensator according to the control signaling
  • the amount of compensation is such that the residual dispersion of the wavelength channel satisfies the requirements of the optical receiver's dispersion tolerance.
  • a device for residual dispersion compensation of a wavelength division multiplexing system further includes a transmitting end optical signal control device, which is connected to the central control device through a digital communication network, and is configured to adjust and control the transmitting end light source according to the control signaling to make the wavelength
  • the residual dispersion of the channel meets the requirements of the optical receiver.
  • the performance parameter may be a bit error rate of the receiving end or a Q value of the optical signal of the receiving end.
  • the performance parameter detecting device comprises a Q value detecting device, a channel switching switch and a beam splitting device which are sequentially connected, wherein: the Q value detecting device is configured to detect the Q value of the optical signal at the receiving end, and the Q value The detection result is sent to the central control device; the light splitting device is disposed before the receiver, and is used for separating part of the light from the receiving end optical signal, and transmitting the light to the Q value detecting device through the channel switching switch; and the channel switching switch, and the adjustable The dispersion compensator control device is coupled and controlled by the tunable dispersion compensator control device for effecting switching of the wavelength channel during the residual dispersion adjustment process.
  • the performance parameter may be the amount of residual dispersion of the actual fiber channel of the optical signal at the receiving end.
  • the performance parameter detecting means comprises an actual residual dispersion detecting means, a channel switching switch and a beam splitting device which are sequentially connected, wherein: the actual residual dispersion detecting means for detecting the residual dispersion of the actual fiber channel of the optical signal at the receiving end And send the detection result of the residual amount of the actual Fibre Channel to the central control device; the spectroscopic device is disposed before the receiver, and is used to separate part of the light from the optical signal of the receiving end, and send it to the actual through the channel switching switch a residual dispersion detecting device; and a channel switching switch connected to the tonable dispersion compensator control device and controlled by the tonable dispersion compensator control device for effecting the cutting of the wavelength channel during the residual dispersion adjustment process Change.
  • the performance parameter detecting means comprises an actual residual dispersion detecting means, a tunable filter and a beam splitting device which are sequentially connected, wherein: the actual residual dispersion detecting means is for detecting the actual optical fiber of the receiving end optical signal The residual dispersion of the channel, and the detection result of the residual dispersion of the actual fiber channel is sent to the central control device; the optical splitting device is used to split the partial light from the multiplex section before the receiver and send it to the actual residual through the tunable filter A dispersion detecting device; and a tunable filter coupled to the tunable dispersion compensator control device and controlled by the tunable dispersion compensator control device for effecting switching of the wavelength channel during the residual dispersion adjustment process.
  • Another aspect of the present invention also provides a wavelength division multiplexing system, including an optical signal transmitting subsystem, an optical signal multiplexing segment transmission subsystem, and an optical signal receiving subsystem, and a device for residual dispersion compensation of a wavelength division multiplexing system.
  • the device for residual dispersion compensation of the wavelength division multiplexing system comprises a performance parameter detecting device, a central control device and a tonable dispersion compensator control device, wherein: the performance parameter detecting device is configured to receive and detect performance parameters of the optical signal at the receiving end, And transmitting the detection result of the performance parameter to the central control device; the central control device is configured to determine the dispersion adjustment mode according to the detection result of the performance parameter, and send the control to the tunable dispersion compensator control device through the control signaling; The dispersion compensator control device is configured to adjust the dispersion compensation amount of the tunable dispersion compensator at the receiving end of the wavelength division multiplexing system according to the control signaling, so that the residual dispersion of the wavelength channel satisfies the requirements of the optical receiver.
  • a device for residual dispersion compensation of a wavelength division multiplexing system further includes: a transmitting end optical signal control device connected to the central control device through a digital communication network, configured to adjust and control the transmitting end light source according to the control signaling, The residual dispersion of the wavelength channel is made to meet the requirements of the optical receiver.
  • the performance parameter is the bit error rate of the optical signal at the receiving end or the Q value of the optical signal at the receiving end.
  • the performance parameter detecting apparatus includes a Q value detecting device and a channel switching switch and a beam splitting device which are sequentially connected, wherein: the Q value detecting device is configured to detect the Q value of the optical signal at the receiving end, and Q The detection result of the value is sent to the central control device; the light splitting device is disposed before the receiver, and is used for separating part of the light from the optical signal of the receiving end, and transmitting the light to the Q value detecting device through the channel switching switch; and the channel switching switch, The tunable dispersion compensator control device is coupled and controlled by the tunable dispersion compensator control for effecting switching of the wavelength channels during the residual dispersion adjustment process.
  • a performance parameter detecting apparatus includes an actual residual dispersion detecting device, a channel switching switch, and a beam splitting device sequentially connected, wherein: the actual residual dispersion detecting device is configured to detect an actual fiber channel of the optical signal at the receiving end The amount of residual dispersion, and the detection result of the residual amount of the actual fiber channel is sent to the central control device; the light splitting device is disposed before the receiver, and is used to separate part of the light from the receiving end optical signal and send it through the channel switching switch The actual residual dispersion detecting means; and the channel switching switch are connected to the tunable dispersion compensator control means and controlled by the tunable dispersion compensator control means for switching the wavelength channel during the residual dispersion adjustment process.
  • the performance parameter detecting device includes an actual residual dispersion detecting device, a tunable filter, and a beam splitting device sequentially connected, wherein: the actual residual dispersion detecting device is configured to detect the optical signal at the receiving end The amount of residual dispersion of the actual Fibre Channel, and sends the detection result of the residual amount of the actual Fibre Channel to the central control device; the splitting device is used to layer part of the light from the multiplex section before the receiver and send it through the tunable filter An actual residual dispersion detecting device; and a tunable filter are coupled to the tunable dispersion compensator control device and controlled by the tunable dispersion compensator control device for effecting switching of the wavelength channel during the residual dispersion adjustment process.
  • Step A The performance parameter detecting device receives and detects performance parameters of the optical signal at the receiving end, and performs performance parameters.
  • the detection result is sent to the central control device;
  • Step B the central control device determines the dispersion adjustment mode according to the detection result of the performance parameter, and sends the control to the tunable dispersion compensator control device; and
  • step C the chromatic dispersion compensation
  • the device control device adjusts the dispersion compensation amount of the tunable dispersion compensator at the receiving end of the wavelength division multiplexing system according to the control signaling, so that the residual chromatic dispersion of the wavelength channel satisfies the requirements of the optical receiver.
  • the performance parameter may be the bit error rate at the receiving end, the Q value, or the amount of residual dispersion of the actual fiber channel.
  • Still another aspect of the present invention provides a method for residual dispersion compensation of a wavelength division multiplexing system, comprising the steps of: Step A: adjusting residual dispersion of wavelength channels at both ends of the system according to the number of channels of the system; Step B, adjusting the middle Residual dispersion of the wavelength channel; and step C, according to step A And the adjustment amount of the dispersion compensation of the both-end wavelength channel and the intermediate wavelength channel obtained in the step B to adjust the dispersion compensation amount of the channel adjacent to the two-end wavelength channel or the intermediate wavelength channel.
  • FIG. 1 is a graph showing a dispersion coefficient characteristic of a G.652 fiber
  • FIG. 2 is a schematic diagram of dispersion compensation of a high-speed wavelength division multiplexing optical transmission system in a multiplexing section
  • FIG. 3 is a current wavelength division multiplexing optical transmission system. Schematic diagram of residual dispersion after dispersion compensation
  • FIG. 4 is a high-speed wavelength division multiplexing optical transmission system for performing residual dispersion compensation using an EDC device
  • FIG. 5 is a schematic structural view of a wavelength division multiplexing system according to the present invention
  • FIG. 7 is a schematic diagram of a residual dispersion distribution before and after dynamic dispersion compensation of a wavelength division multiplexing optical transmission system of the present invention
  • FIG. 8 is a BER detection using the BER according to the present invention
  • FIG. 9 is a schematic structural diagram of a wavelength division multiplexing system for performing dispersion compensation using Q value detection according to the present invention
  • FIG. 10 is a schematic diagram of an actual optical fiber using a multiplex section layer according to the present invention
  • FIG. 11 is a residual of the actual fiber channel using the channel layer of the present invention
  • FIG. 12 of the present invention in a multiplex section layer using tunable dispersion compensator to compensate for dispersion Schematic diagram of the structure of the wavelength division multiplexing optical transmission system
  • the wavelength division multiplexing system includes an optical signal transmitting subsystem 10, an optical signal multiplexing section transmission subsystem 20, and a light that are sequentially connected.
  • the dispersion compensation module includes forward dispersion compensation. The module mode, the line dispersion compensation module mode, and the backward dispersion compensation module mode.
  • the optical signal receiving subsystem 30 includes a light receiver 301 (Rx) and a tonable dispersion compensation module 302.
  • the tunable dispersion compensation module 302 is disposed before the optical receiver 301 of each wavelength channel at the receiving end, and is connected every time.
  • the wavelength division multiplexing system further includes a residual dispersion compensation subsystem 40 for determining a dispersion adjustment mode according to a performance parameter of the Rx received optical signal, and adjusting and controlling the tunable dispersion compensation according to the determined dispersion adjustment mode.
  • the residual dispersion compensation subsystem 40 includes: a performance parameter detecting device 401, a center control device 402, a tunable dispersion compensator control device 403, and a transmitting end optical signal control device 404, wherein: the performance parameter detecting device 401 For receiving and detecting the performance parameter sent by the optical receiver Rx, and transmitting the detection result of the performance parameter to the central control device 402; the central control device 402 is configured to determine the dispersion adjustment mode according to the detection result of the performance parameter, and pass the control signaling Transmitted to the tunable dispersion compensator control device 403 and the transmitting end optical signal control device 404; the tunable dispersion compensator control device 403 is configured to adjust according to the control signaling of the central control device 402 a dispersion compensation amount
  • a certain length sequence of pseudo-random code (PRBS) signals, etc., are included in the source of the adjustment control transmitter. Since the transmitter adjustment control is not a necessary flow, it is not included in the flowchart of FIG. Wherein, the tunable dispersion compensator 403 and the transmitting optical signal control device 404 respectively adjust and control the tunable dispersion and the transmitting end light source, thereby realizing dynamic control of dispersion compensation, so that the optical signal is The receiving end meets the requirements of the optical receiver.
  • 6 is a flowchart of a method for residual dispersion compensation of a wavelength division multiplexing system according to the present invention. FIG. 6 is described below with reference to FIG. 5. As shown in FIG.
  • Step 601 The performance parameter detecting device 401 refers to the reference The performance parameters of the wavelength channel K and the edge wavelength channel L, N are detected and the detection result of the performance parameter is reported to the central control device 402.
  • step 602 the central control device 402 performs dispersion according to the performance parameter detection result reported by the performance parameter detecting device 401.
  • the curve offset is diagnosed, and it is judged whether the performance parameter exceeds the limit. If yes, the process proceeds to step 603, otherwise, the process returns to step 601 to continue to detect the performance parameter and is up; 603, the central control device 402 according to the reference wavelength channel K and Edge wavelength channel
  • the performance parameter detection result of L and N determines the dispersion adjustment mode, and is sent to the tunable dispersion compensator control device 403 through control signaling; step 604, the tunable dispersion compensator control device 403 sequentially adjusts the reference according to the control signaling
  • the dispersion compensation amount of the tunable dispersion compensator of the wavelength channel K and the edge wavelength channels L, N respectively makes the performance parameters of the reference wavelength channel K and the edge wavelength channels L, N satisfy the requirements; in step 605, the central control device 402 records the reference respectively.
  • Step 606 the reference wavelength channel K and the edge wavelength channel L obtained according to step 605, respectively N adjusts the dispersion compensation amount of the tunable dispersion compensator of the adjacent wavelength channel after the performance parameter satisfies the requirement, so that the residual dispersion of all channels of the wavelength division multiplexed optical transmission system satisfies the requirements, and then returns to the step 601.
  • 7 is a schematic diagram showing the comparison of the residual dispersion distribution of the wavelength channel of the wavelength division multiplexing optical transmission system before and after the dynamic dispersion compensation of the present invention. As shown in FIG.
  • the solid curve is a schematic diagram of residual dispersion without dynamic dispersion compensation, and a virtual curve.
  • the small black dots in the figure represent the residual dispersion magnitude of each wavelength channel after dynamic dispersion compensation.
  • the wavelength division multiplexing optical transmission system is long.
  • the residual dispersion values of the wavelength channels after the transmission are within the allowable dispersion tolerance of the receiver. The invention will be further described below using more detailed examples.
  • the detecting device 401 adopts a commonly used error test method, and can directly access an SDH (Synchronous Digital Hierarchy) signal through an OTU (Optical Transmitting Unit) board, and accesses the system through the transmitting end.
  • SDH Serial Digital Hierarchy
  • OTU Optical Transmitting Unit
  • the central control device 402 determines the dispersion adjustment mode according to the reported performance parameter of the BER detection device 401, and transmits the chromatic dispersion adjustment mode to the tunable dispersion compensator control device 403 and transmits the control signal.
  • the end light signal control device 404 adjusts the dispersion compensation amount of the tonable dispersion compensator by the tonable dispersion compensator control device 403 to realize dynamic control of the dispersion compensation, so that the optical signal satisfies the requirements of the optical receiver at the receiving end.
  • the present invention can place an error generator on the transmitting end to generate a pseudo-random code modulated signal of a certain sequence length, and then access it to each wavelength path of the wavelength division multiplexing system, and the BER detecting device 401 detects The specific pseudo-random code modulates the bit error rate of the signal, thereby implementing dynamic control of dispersion compensation.
  • the tunable dispersion compensator may also be disposed at the transmitting end of the wavelength division multiplexing, or simultaneously set in the wavelength division multiplexing Use the receiver and sender of the system.
  • the method for residual dispersion compensation of the wavelength division multiplexing system of the present invention may further include the following steps: Step 1, the BER detecting device 401 detects the BER of the reference wavelength channel K and the edge wavelength channels L, N, respectively, and reports the detection result to the central control device 402.
  • Step 2 the central control device 402 according to the performance parameter: the detecting device 401
  • the reported BER detection result is subjected to dispersion curve offset diagnosis, and it is judged whether the performance parameter exceeds the limit. If "Yes", the process proceeds to step 3. Otherwise, the process returns to step 1 to continue detecting the BER and uploads.
  • the central control device 402 will test the path. Switching to the reference wavelength channel K, the wavelength is ⁇ ⁇ , wherein the selection principle of the reference channel is that the dispersion compensation amount is the smallest, and the central control device 402 determines the dispersion adjustment mode according to the error rate of the reference wavelength channel ,, and passes the control signaling. Sended to the tunable dispersion compensator control device 403, step four, the tunable dispersion compensator control device 403 adjusts the reference wavelength channel according to the control signaling
  • ⁇ amount of dispersion compensation may be tunable chromatic dispersion compensator, so that the error rate is less than the reference wavelength channel ⁇ far 10_ 12, and record the amount of dispersion compensation at this time tunable dispersion compensator of the reference wavelength channel ⁇ ; step five, Repeat the steps according to three and four, respectively, to adjust the dispersion compensation amount of the tunable dispersion compensator of the edge wavelength channels L, N (wavelengths respectively X L .
  • the performance parameter detecting device 401 at the receiving end is specifically a Q value detecting device and a channel switching switch and an optical switch connected in sequence, wherein:
  • a Q value detecting device configured to detect a Q value of the optical signal at the receiving end, and send the Q value detection result to the central control device;
  • the optical switch is disposed in front of the receiver, and is used to separate part of the light from the receiving end optical signal, And is sent to the Q value detecting device through the channel switching switch;
  • the channel switching switch is connected with the tunable dispersion compensator control device, and is controlled by the tonable dispersion compensator control device for realizing the wavelength in the residual dispersion adjustment process Channel switching.
  • the processing flow basis of the wavelength dispersion multiplexing system residual dispersion compensation method is based on the processing flow basis. The same is true, and will not be repeated here.
  • the previous BER detection can be directly reported through the OTU of each path, so no channel switching is required.
  • the channel switch can be directly controlled by the tunable dispersion compensation controller and determined in a certain channel.
  • the performance parameter detecting apparatus of the receiving end in FIG. 5 As shown in FIG. 5, FIG. 8 and FIG. 10, in the wavelength division multiplexing system of the present invention, the performance parameter detecting apparatus of the receiving end in FIG.
  • the actual residual dispersion detecting device is configured to detect the residual dispersion amount of the actual fiber channel at the receiving end, and send the detection result of the residual dispersion amount of the actual fiber channel to the central control device;
  • the optical separating device is used for the recovery from the front of the receiver Part of the light is separated by the segment layer and sent to the actual residual dispersion detecting device through the tunable filter;
  • the tunable filter is connected to the tunable dispersion compensator control device and controlled by the tonable dispersion compensator control device, The switching of the wavelength channel is implemented during the residual dispersion adjustment process.
  • bit error rate (bit error rate) detecting device is basically the same as the performance parameter detecting device, and the processing flow of the method for residual dispersion compensation of the wavelength division multiplexing system is basically the same, and will not be described herein.
  • this embodiment also achieves control of the control tunable dispersion compensator by detecting the actual dispersion residual, which differs from the embodiment shown in Figure 10 in that the actual dispersion residual detecting means 401" The method for detecting the light and the switching channel is different.
  • the performance parameter detecting device specifically includes an actual residual dispersion detecting device, a channel switching switch and an optical switch, which are sequentially connected, wherein: the actual residual dispersion detecting device is configured to detect the residual dispersion of the actual fiber channel at the receiving end. And send the detection result of the residual amount of the actual Fibre Channel to the central control device; the optical switch is disposed in front of the receiver, and is used to separate part of the light from the optical signal of the receiving end, and send it to the actual residual through the channel switching switch A dispersion detecting device; a channel switching switch, and a tonable dispersion compensator control device, and controlled by the tunable dispersion compensator control means for switching the wavelength channel during the residual dispersion adjustment process.
  • the optical switch can also be other forms of optical splitting devices.
  • the processing flow of the method for residual dispersion compensation of the wavelength division multiplexing system in this manner is substantially the same as that of the previous method, and details are not described herein again.
  • the chromatic dispersion compensation module of the multiplex section in the wavelength division multiplexing system can also adopt a controllable tunable dispersion compensator instead of the traditional fiber dispersion compensation device, and the chromatic dispersion can be used.
  • the compensator control device realizes the adjustment of each tunable dispersion compensator, realizes the dynamic control of the dispersion compensation, and enables the optical signal to meet the requirements of the optical receiver at the receiving end.
  • the tunable dispersion compensator can only be used in a specific position of the wavelength division multiplexed optical transmission system to be controlled by the control device.
  • the tunable dispersion compensator at the receiving end cannot function in the line, and can not be controlled by the DCN. It works.
  • the dashed line indicates that many segments of the transmitted fiber link can be used and are remote control of the principle control center.
  • a tunable dispersive device can be used to replace the conventional DCM device every 80 km. Its control process is as before.
  • the invention also provides a method for residual dispersion compensation of a wavelength division multiplexing system (ie, a three-point detection control feedback method), which comprises the following steps: Step A, adjusting residual dispersion of wavelength channels at both ends of the system according to the number of channels of the system Step B, adjusting the residual dispersion of the intermediate wavelength channel; and step C, adjusting the wavelength channel or the intermediate wavelength according to the adjustment amount of the dispersion compensation of the both end wavelength channel and the intermediate wavelength channel obtained in steps A and B
  • the amount of dispersion compensation for the channel adjacent to the eye. 13 and FIG. 14 show two special cases of the method of the present invention. In FIG.
  • the residual dispersion values of each wavelength channel of the system are positive residual dispersion values, as shown by the solid curve in FIG.
  • the above three-point detection control feedback method can be converted into two-point detection control, as long as the residual dispersion compensation amount of the edge wavelength channel is detected, and then the dispersion compensation amounts of the two edge channels are appropriately referenced to appropriately adjust other adjacent channels.
  • the amount of dispersion compensation finally compensates the residual dispersion of all channels of the wavelength division multiplexed optical transmission system to the allowable dispersion tolerance of the receiver, as shown by the dashed curve in Fig. 13.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Optical Communication System (AREA)

Description

波分复用系统及其残余色散补偿的方法和装置 技术领域 本发明涉及 WDM ( Wavelength Division Multiplexing, 波分复用） 系统 及其残佘色散补偿的调节方法和装置， 更具体地， 涉及波分复用系统及对波 分复用光传输系统复用段进行色散补偿以后的各通道残余色散补偿的方法和 装置。 背景技术 随着波分复用光传输系统单通道速率不断提高（例如目前骨干传送网信 号速率大都从 2.5Gb/s升级到 10Gb/s ),作为光传输介质的单模光纤重要物理 特性之一的色散已成为高速光传输系统传输距离受限的主要因素。 以波分复用系统通常使用的普通 G.652单模光纤的色散特性为例，零色 散波长在 1310nm附近， 如图 1的虚线所示， 而波分复用光传输系统通常工 作在 C波段 1550nm附近， 具体来说工作在 C波段的波长范围是 1529.16nm 到 1560.61nm, 而 1550nm传输波长附近的色散系数约为 17ps/nm/km, 如果 要达到满足光信噪比 （OSNR )要求的 640km传输， 色散累积将达到 11000 ps/nm, 远大于 10Gb/s激光器光源的色散容纳值（如目前 80km电吸收激光 器的色散容纳值为 1600ps/nm；), 因而高速波分复用光传输系统必须进行色散 补偿以后才能满足实际传输的要求。 图 1中的实曲线为经过色散补偿光纤进 行色散补偿以后光纤的色散系数曲线， 显然只能在 C波段的某一个中心波长 附近， 色散补偿光纤可以周期性的使光纤链路累积的色散达到最小， 但是在 中心波长两边的其它波长， 尤其是边缘波长（如 1529.16nm、 1560.61nm )的 色散系数很大， 经过多跨段的传输以后， 残余色散会增加许多。 目前高速波分复用光传输系统通常可以在复用段或单通道进行色散补 偿。 在复用段进行色散补偿时， 如图 2所示， 一般在传输链路中周期性的加 入 DCM (Dispersion Compensating Module, 色散补偿模块）， 其中包括： 前向色散补偿方式， 利用前向色散补偿模块（光纤色散补偿模块设置于 后置光放大器之前）进行色散预补偿； 线路色散补偿方式， 利用线路色散补偿模块 (光纤色散补偿模块设置于 线路光放大器之间）进行线路色散补偿； 后向色散补偿方式， 利用后向色散补偿模块 (光纤色散补偿模块设置于 前置光放大器之后 )进行色散后补偿。 对于中短距离的波分复用光传输系统，通过以上方式可以解决光纤色散 问题 , 使传输系统的残余色散在接收机允许的色散容限范围以内。 但是由于普通光纤和色散补偿模块的相对色散斜率不一定相同，在通道 数量较多、 传输距离很远时， 即使某一个波长通道的残余色散完全被优化而 误码率最低， 而其他通道（尤其是边缘波长通道） 的残余色散仍可能很大， 很难保证传输后没有误码。图 3给出了波分复用光传输系统残余色散示意图， 其中 D+和 D-是接收机允许的色散容限范围， D+ma 和 D-max分别表示累 积的正残余色散和负残余色散的最大值。 如图 3所示， 色散补偿光纤只能将 某一中心波长累积色散补偿到最小， 而其他中心波长还是存在较大的累积残 余色散， 因此， 即便在波分系统的复用段采用可调色散补偿器也很难精确地 将所有通路的色散都补偿到最佳效果， 因此各通路的色散过补偿和欠补偿是 难于避免的。 残余色散的累积对于超长距离的光传输系统危害很大， 甚至会 导致光传输系统的崩溃。 在波长通道层对每一个波长通道分别采用不同补偿量的色散补偿模块 进行色散补偿时， 一般将它们集成在波分复用光传输系统的接收端， 对系统 残余色散的影响起到一定的补偿作用， 图 4 是一种采用 EDC ( Electrical Dispersion Compensation, 电色散 卜偿）器件的高速波分复用光传输系统的残 余色散补偿方法。 然而这种方法存在的问题是，电色散补偿器件的色散补偿量固定且十分 有限， 只能在一定程度上减小系统残余色散带来的影响， 不能从根本上解决 系统存在的残余色散问题， 更不能动态调节波分复用系统各波长通道的色散 补偿量， 由于其色散补偿量的不可调节， 应用在实际波分复用光传输系统中 缺少灵活性。 发明内容 本发明的目的在于提供一种波分复用系统及其残余色散补偿的方法和 装置 , 利用可调 b色散补偿器件对波分复用光传输系统复用段采用光纤色散 补偿模块集中补偿后的通道层的残余色散进行补偿， 优化每个通道的残余色 散， 解决长距离光传输系统残余色散所引起的传输性能劣化的问题。 为了实现上述目的，本发明的一个方面提供了一种波分复用系统残余色 散补偿的装置， 包括性能参数检测装置、 中心控制装置和可调色散补偿器控 制装置， 其中： 性能参数检测装置， 用于接收并检测接收端光信号的性能参 数， 并将性能参数的检测结果发送到中心控制装置； 中心控制装置， 用于根 据性能参数的检测结果确定可调谐色散补偿器的色散调节方式， 并通过控制 信令发送给可调色散补偿器控制装置； 以及可调色散补偿器控制装置， 用于 接收中心控制装置发送的控制命令并根据控制信令调节可调色散补偿器的色 散补偿量， 使波长通道的残余色散满足光接收器色散容限的要求。 根据本发明的一个方面，波分复用系统残余色散补偿的装置还包括发送 端光信号控制装置， 通过数字通信网与中心控制装置连接， 用于根据控制信 令调节控制发送端光源， 使波长通道的残余色散满足光接收器的要求。 其中， 性能参数可以为接收端的误码率、 或接收端光信号的 Q值。 根据本发明的一个方面， 性能参数检测装置包括依次连接的 Q值检测 装置、 通道切换开关和分光器件， 其中： Q值检测装置， 用于检测接收端光 信号的 Q值， 并将 Q值的检测结果发送到中心控制装置； 分光器件， 设置于 接收机之前， 用于从接收端光信号中分出部分光， 并通过通道切换开关发送 给 Q值检测装置； 以及通道切换开关， 与可调色散补偿器控制装置连接， 并 由可调色散补偿器控制装置控制， 用于在残余色散调整过程中实现波长通道 的切换。 其中， 性能参数可以为接收端光信号的实际光纤通道的残余色散量。 根据本发明的一个方面，性能参数检测装置包括依次连接的实际残余色 散检测装置、 通道切换开关和分光器件， 其中： 实际残余色散检测装置， 用 于检测接收端光信号的实际光纤通道的残余色散量， 并将实际光纤通道的残 余色散量的检测结果发送到中心控制装置； 分光器件， 设置于接收机之前， 用于从接收端光信号中分出部分光， 并通过通道切换开关发送给实际残余色 散检测装置； 以及通道切换开关， 与可调色散补偿器控制装置连接， 并由可 调色散补偿器控制装置控制， 用于在残余色散调整过程中实现波长通道的切 换。 另夕卜，根据本发明的一个方面， 性能参数检测装置包括依次连接的实际 残余色散检测装置、 可调谐滤波器和分光器件， 其中： 实际残余色散检测装 置用于检测接收端光信号的实际光纤通道的残余色散量， 并将实际光纤通道 的残余色散量的检测结果发送到中心控制装置； 分光器件用于从接收机前的 复用段层分部分光并通过可调谐滤波器发送给实际残余色散检测装置； 以及 可调谐滤波器与可调色散补偿器控制装置连接， 并由可调色散补偿器控制装 置控制， 用于在残余色散调整过程中实现波长通道的切换。 本发明的另一个方面还提供了一种波分复用系统，包括光信号发送子系 统、 光信号复用段传输子系统和光信号接收子系统， 还包括波分复用系统残 余色散补偿的装置， 波分复用系统残余色散补偿的装置包括性能参数检测装 置、 中心控制装置和可调色散补偿器控制装置， 其中： 性能参数检测装置， 用于接收并检测接收端光信号的性能参数， 并将性能参数的检测结果发送到 中心控制装置； 中心控制装置， 用于根据性能参数的检测结果确定色散调节 方式， 并通过控制信令发送给可调色散补偿器控制装置； 以及可调色散补偿 器控制装置， 用于根据控制信令调节波分复用系统接收端的可调色散补偿器 的色散补偿量， 使波长通道的残余色散满足光接收器的要求。 根据本发明的另一个方面 , 波分复用系统残余色散补偿的装置还包括： 发送端光信号控制装置 , 通过数字通信网与中心控制装置连接， 用于根据控 制信令调节控制发送端光源， 使波长通道的残余色散满足光接收器的要求。 其中， 性能参数为接收端光信号的误码率、 或接收端光信号的 Q值。 另外根据本发明的另一个方面， 性能参数检测装置包括依次连接的 Q 值检测装置和通道切换开关和分光器件， 其中： Q值检测装置， 用于检测接 收端光信号的 Q值， 并将 Q值的检测结果发送到中心控制装置； 分光器件， 设置于接收机之前， 用于从接收端光信号中分出部分光， 并通过通道切换开 关发送给 Q值检测装置； 以及通道切换开关， 与可调色散补偿器控制装置连 接， 并由可调色散补偿器控制装置控制， 用于在残余色散调整过程中实现波 长通道的切换。 其中， 性能参数为接收端光信号的实际光纤通道的残余色散量。 才艮据本发明的另一个方面 ,性能参数检测装置包括依次连接的实际残余 色散检测装置、 通道切换开关和分光器件， 其中： 实际残余色散检测装置用 于检测接收端光信号的实际光纤通道的残余色散量， 并将实际光纤通道的残 余色散量的检测结果发送到中心控制装置； 分光器件， 设置于接收机之前， 用于从接收端光信号中分出部分光， 并通过通道切换开关发送给实际残余色 散检测装置； 以及通道切换开关， 与可调色散补偿器控制装置连接， 并由可 调色散补偿器控制装置控制， 用于在残余色散调整过程中实现波长通道的切 换。 另夕卜，根据本发明的另一个方面， 性能参数检测装置包括依次连接的实 际残余色散检测装置、 可调谐滤波器和分光器件， 其中： 实际残余色散检测 装置， 用于检测接收端光信号的实际光纤通道的残余色散量， 并将实际光纤 通道的残余色散量的检测结果发送到中心控制装置； 分光器件， 用于从接收 机前的复用段层分部分光并通过可调谐滤波器发送给实际残余色散检测装 置； 以及可调谐滤波器， 与可调色散补偿器控制装置连接， 并由可调色散补 偿器控制装置控制， 用于在残余色散调整过程中实现波长通道的切换。 本发明的又一个方面还提出了一种波分复用系统残余色散补偿的方法， 包括 ^下步骤： 步驟 A, 性能参数检测装置接收并检测接收端光信号的性能参数， 并将 性能参数的检测结果发送到中心控制装置； 步骤 B, 中心控制装置根据性能参数的检测结果确定色散调节方式， 并 通过控制信令发送给可调色散补偿器控制装置； 以及 步骤 C,可调色散补偿器控制装置根据控制信令调节波分复用系统接收 端的可调色散补偿器的色散补偿量， 使波长通道的残余色散满足光接收器的 要求。 其中， 性能参数可以为接收端误码率、 Q值或实际光纤通道的残余色散 量等。 本发明的再一个方面提供了一种波分复用系统残余色散补偿的方法，其 包括以下步驟： 步骤 A , 根据系统的通道数调节系统的两端波长通道的残余 色散； 步骤 B, 调节中间波长通道的残余色散； 以及步骤 C, 根据在步骤 A 和步驟 B中得到的两端波长通道和中间波长通道的色散补偿的调节量来调节 与两端波长通道或中间波长通道相邻的通道的色散补偿量。 本发明的波分复用系统残余色散补偿的调节方法和装置，通过检测接收 端光信号的性能参数， 动态反馈调整可调谐色散补偿器， 实现波分复用光传 输系统残余色散的动态控制， 有效地解决了大容量远距离波分复用光传输系 统残余色散累积的技术问题， 实现了大容量波分复用光传输系统超长距离传 输。 附图说明 图 1为 G.652光纤的色散系数特性曲线图； 图 2为目前高速波分复用光传输系统在复用段进行色散补偿的示意图； 图 3为目前波分复用光传输系统进行色散补偿后的残余色散示意图； 图 4为采用 EDC器件进行残余色散补偿的高速波分复用光传输系统； 图 5为本发明的波分复用系统的结构示意图； 图 6为本发明的波分复用系统残余色散补偿的方法流程图； 图 7 为本发明的波分复用光传输系统的波长通道经过动态色散补偿前 后的残余色散分布对比示意图； 图 8为本发明的利用 BER检测进行色散补偿的波分复用系统的结构示 意图； 图 9为本发明的利用 Q值检测进行色散补偿的波分复用系统的结构示 意图； 图 10为本发明的利用对复用段层实际光纤通道的残余色散量检测进行 色散补偿的波分复用系统的结构示意图； 图 11为本发明的利用对通道层实际光纤通道的残余色散量检测进行色 散补偿的波分复用系统的两种结构示意图； 图 12为本发明的在复用段层采用可调谐色散补偿器来进行色散补偿的 波分复用光传输系统结构示意图； 以及 图 13和图 14为本发明的两种特例经过动态色散 卜偿前后的残余色散分 布对比示意图。 具体实施方式 图 5为本发明的波分复用系统的结构示意图 , 如图 5所示， 波分复用系 统包括依次连接的光信号发送子系统 10、 光信号复用段传输子系统 20和光 信号接收子系统 30, 其中： 信号复用段传输子系统 20包括依次连接的合波器 201、 色散补偿模块 202和分波器 203， 如图 5所示， 该色散补偿模块包括前向色散补偿模块方 式、 线路色散补偿模块方式和后向色散补偿模块方式， 当然， 在实际应用中， 可以是这三者中的任意一个或多个的组合。 其中 , 光信号接收子系统 30包括光接收器 301 ( Rx )和可调色散补偿 模块 302, 该可调色散补偿模块 302设置于接收端每一波长通道的光接收器 301之前， 连接每一波长通道的光接收器 301和分波器 203。 另外， 波分复用系统还包括残余色散补偿子系统 40， 用于才艮据 Rx接收 到光信号的性能参数确定色散调节方式， 并根据确定出的色散调节方式调节 和控制可调色散补偿模块 302和光信号发送子系统 10中的光发射器 （ Tx ), 实现色散补偿的动态控制， 最终使光信号满足光接收器色散容限的要求。 如图 5所示， 残余色散补偿子系统 40包括： 性能参数检测装置 401、 中心控制装置 402、 可调色散补偿器控制装置 403和发送端光信号控制装置 404, 其中： 性能参数检测装置 401用于接收并检测光接收器 Rx发送的性能参数， 并将性能参数的检测结果发送到中心控制装置 402; 中心控制装置 402用于根据性能参数的检测结果确定色散调节方式，并 通过控制信令发送给可调色散补偿器控制装置 403和发送端光信号控制装置 404; 可调色散补偿器控制装置 403用于根据中心控制装置 402的控制信令调 节接收端的可调色散补偿器的色散补偿量； 以及 发送端光信号控制装置 404 , 可通过 DCN ( Data Communication Network, 数据通信网）连接中心控制装置 402， 用于根据中心控制装置 402 的控制信令调节控制发送端光源； 比如调节发送端光源的电色散补偿功能使 能， 如果发送端的电色散补偿是可调谐的， 则可以调节发送端的目标色散补 偿值、可直接控制光发送端发出调制的一定长度序列的伪随机码 ( PRBS )信 号等均属于包含在调节控制发送端光源里。 由于发送端调节控制并不是必要 流程 , 所以在图 6的流程图中没有包含进去。 其中， 通过可调色散补偿器控制装置 403和发送端光信号控制装置 404 分别对可调色散补棲器和发送端光源的调节和控制， 实现了色散补偿的动态 控制， 使光信号在接收端满足光接收器的要求。 图 6为本发明的波分复用系统残余色散补偿的方法流程图 ,下面结合图 5对图 6进行描述， 如图 6所示， 包括如下步骤： 步驟 601 ,性能参数检测装置 401分別对参考波长通道 K和边缘波长通 道 L、 N的性能参数进行检测并将性能参数的检测结果上报给中心控制装置 402； 步骤 602, 中心控制装置 402根据性能参数检测装置 401上报的性能参 数检测结果进行色散曲线偏移诊断， 并判断性能参数是否越限， 如果 "是"， 则进入步骤 603 , 否则返回步骤 601继续检测性能参数并上才艮； 步骤 603 ,中心控制装置 402分别根据参考波长通道 K和边缘波长通道
L、 N 的性能参数检测结果确定色散调节方式， 并通过控制信令发送到可调 色散补偿器控制装置 403; 步驟 604, 可调色散补偿器控制装置 403根据控制信令分別依次调节参 考波长通道 K和边缘波长通道 L、 N的可调谐色散补偿器的色散补偿量， 分 别使参考波长通道 K和边缘波长通道 L、 N的性能参数满足要求； 步驟 605，中心控制装置 402分别记录参考波长通道 K和边缘波长通道 L、 N的性能参数满足要求后的色散补偿量； 步骤 606,分别根据步骤 605得到的参考波长通道 K、边缘波长通道 L、 N在性能参数满足要求后的色散补偿量对其相邻波长通道的可调谐色散补偿 器的色散补偿量进行调节， 使波分复用光传输系统所有通道的残余色散均满 足要求， 然后返回步骤 601。 图 7 是波分复用光传输系统的波长通道经过本发明的动态色散补偿前 后的残余色散分布对比示意图， 如图 7所示， 实曲线为没有经过动态色散补 偿的残余色散的示意图， 虚曲线为经过动态色散 卜偿的残余色散的示意图， 图中小黑点代表经过动态色散补偿以后每个波长通道的残余色散量值， 经过 本发明的动态色散补偿， 波分复用光传输系统经过长距离传输以后各波长通 道的残余色散值均处于接收机允许的色散容限范围内。 下面进一步利用更加详细的例子对本发明进行进一步说明。 结合图 5和图 8所示，在根据本发明的波分复用系统中， 图 5中接收端 的性能参数检测装置 401具体为 BER( Bit Error Rate,误码率）检测装置 401，， 该 BER检测装置 401，采用通常使用的误码测试的方法， 可直接使用 OTU ( Optical Transform Unit, 光转发单元 )单板接入 SDH ( Synchronous Digital Hierarchy , 同步数字序列）信号， 通过发送端接入到系统的波长通道中 , 中 心控制装置 402根据 BER检测装置 401，上报的性能参数， 在此为误码率， 确定色散调节方式， 并通过控制信令发送给可调色散补偿器控制装置 403和 发送端光信号控制装置 404, 由可调色散补偿器控制装置 403调节可调色散 补偿器的色散补偿量， 实现色散补偿的动态控制， 使光信号在接收端满足光 接收器的要求。 同时， 本发明可以在发送端放置一个误码发生器， 用来产生一定序列长 度的伪随机码调制信号， 然后接入到波分复用系统的各波长通路中， 由 BER 检测装置 401，检测该特定伪随机码调制信号的误码率， 进而实现色散补偿的 动态控制。 同时， 图 5和图 8中的可调色散补偿器设置于波分复用系统的接收端， 但该可调色散补偿器也可以设置于波分复用的发送端， 或同时设置于波分复 用系统的接收端和发送端。 使用 BER ( Bit Error Rate ,误码率）检测装置作为性能参数检测装置时， 本发明的波分复用系统残余色散补偿的方法还可以包括如下步骤： 步骤一， BER检测装置 401，分别对参考波长通道 K和边缘波长通道 L、 N的 BER进行检测并将检测结果上报给中心控制装置 402; 步骤二， 中心控制装置 402根据性能参 ：检测装置 401上报的 BER检 测结果进行色散曲线偏移诊断， 并判断性能参数是否越限， 如果 "是" 则进 入步 三， 否则返回步骤一继续检测 BER并上艮； 步骤三 , 中心控制装置 402将测试通路切换到参考波长通道 K, 其波长 为 λκ, 其中参考通道的选择原则是色散补偿量最小， 中心控制装置 402根据 参考波长通道 Κ的误码率的情况确定色散调节方式，并通过控制信令发送到 可调色散补偿器控制装置 403, 步骤四，可调色散补偿器控制装置 403根据控制信令调节参考波长通道
Κ的可调谐色散补偿器的色散补偿量，使参考波长通道 Κ的误码率小于 10_12 为止， 并记录下此时参考波长通道 Κ的可调色散补偿器的色散补偿量； 步 五， 重复步據三和四， 分別调节边缘波长通道 L、 N (波长分别为 XL. λΝ ) 的可调谐色散补偿器的色散补偿量， 使边缘波长通道 L、 N的误码 率小于 1(Γ12为止， 并记录下此时边缘波长通道 L、 N的可调色散补偿器的色 散补偿量； 步驟六，才艮据参考通道和边缘通道的色散补偿量，适当调整其它相邻通 道的残余色散， 最终使波分复用系统各波长通道的残余色散位于接收机允许 的范围， 返回步職一。 如图 5和图 9所示，本发明的波分复用系统中， 图 5中接收端的性能参 数检测装置 401具体为依次连接的 Q值检测装置和通道切换开关和光开关， 其中：
' Q值检测装置， 用于检测接收端光信号的 Q值， 并将 Q值检测结果发 送到中心控制装置； 光开关设置于接收机之前， 用于从接收端光信号中分出部分光， 并通过 通道切换开关发送给 Q值检测装置； 通道切换开关， 与可调色散补偿器控制装置相连接， 并由可调色散补偿 器控制装置控制， 用于在残余色散调整过程中实现波长通道的切换。 使用 Q值检测装置作为性能参数检测装置与使用 BER ( Bit Error Rate, 误码率）检测装置作为性能参数检测装置相比， 其波分复用系统残余色散补 偿的方法的处理流程基？ 目同，在此不再赘述。前面的 BER检测可以直接通 过每个通路的 OTU板上报， 所以不需要进行通道切换。 通道切换开关可以 直接由可调色散补偿控制器直接控制， 确定在某个通道中。 如图 5、 图 8和图 10所示， 本发明的波分复用系统中， 图 5中接收端 的性能参数检测装置具体包括依次连接的实际残余色散检测装置、 可调谐滤 波器和分光器件， 其中： 实际残余色散检测装置， 用于检测接收端的实际光纤通道的残余色散 量， 并将实际光纤通道的残余色散量的检测结果发送到中心控制装置； 分光器件，用于从接收机前的复用段层分出部分光并通过可调谐滤波器 发送给实际残余色散检测装置； 可调谐滤波器， 与可调色散补偿器控制装置连接， 并由可调色散补偿器 控制装置控制， 用于在残余色散调整过程中实现波长通道的切换。 使用实际色散残余检测装置 401"，作为性能参数检测装置与使用 BER
( Bit Error Rate, 误码率）检测装置作为性能参数检测装置相比， 其波分复 用系统残余色散补偿的方法的处理流程基本相同， 在此不再赘述。 结合图 10和图 11所示，该实施例也通过检测实际色散残余来实现对控 制可调谐色散补偿器的控制， 与图 10 所示的实施例不同之处在于该实际色 散残余检测装置 401"，取得光和切换通道的方式不同， 性能参数检测装置具 体包括依次连接的实际残余色散检测装置、 通道切换开关和光开关， 其中： 实际残余色散检测装置， 用于检测接收端的实际光纤通道的残余色散 量， 并将实际光纤通道的残余色散量的检测结果发送到中心控制装置； 光开关设置于接收机之前， 用于从接收端光信号中分出部分光， 并通过 通道切换开关发送给实际残余色散检测装置； 通道切换开关， 与可调色散补偿器控制装置， 并由可调色散补偿器控制 装置控制， 用于在残余色散调整过程中实现波长通道的切换。 在此， 光开关也可以是其它形式的分光器件。 由于这种方式下波分复用系统残余色散补偿的方法的处理流程与前面 的方式基本相同， 在此不再赘述。 结合图 5和图 12, 本发明还可以将波分复用系统中复用段的色散补偿 模块也采用可控的可调色散补偿器， 代替传统的光纤色散补偿器件， 利用可 调色散补偿器控制装置实现对各可调色散补偿器的调节， 实现色散补偿的动 态控制， 使光信号在接收端满足光接收器的要求。 可调谐色散补偿器只能用 在波分复用光传输系统的特定位置才能由控制装置控制其产生作用， 在接收 端的可调谐色散补偿器不能在线路中发生作用， 更不能通过 DCN控制在线 路中发生作用。 另外虚线是表明传输的光纤链路中的很多段可以使用且为原 理控制中心的远距离控制， 比如每隔 80km可以用一个可调色散 卜偿器件代 替传统的 DCM器件。 其控制过程如前。 本发明还提供了一种波分复用系统残余色散补偿的方法（即三点检测控 制反馈方法）， 其包括以下步 : 步骤 A, 根据系统的通道数调节系统的两端 波长通道的残余色散； 步骤 B , 调节中间波长通道的残余色散； 以及步骤 C , 根据在步驟 A和步驟 B中得到的两端波长通道和中间波长通道的色散补偿的 调节量来调节与两端波长通道或中间波长通 目邻的通道的色散补偿量。 图 13和图 14为本发明的方法的两种特例， 图 13中， 经过复用段集中 色散补偿以后系统各波长通道的残余色散值均为正残余色散值， 如图 13 中 实曲线所示 , 此时上述的三点检测控制反馈方法可以筒化为两点检测控制， 只要检测边缘波长通道的残余色散补偿量， 然后再参考这两个边缘通道的色 散补偿量适当调节其它相邻通道的色散补偿量， 最终将波分复用光传输系统 所有通道的残余色散补偿到接收机允许的色散容限范围内， 如图 13 虚曲线 所示的结果。 图 14与图 13不同之处为所示为负残余色散值的特殊情况，在此不进行 赘述。 当然， 本发明还可有其它多种实施例，在不背离本发明精神及其实质的 情况下，熟悉本领域的技术人员当可根据本发明作出各种相应的改变和变形， 但这些相应的改变和变形都应属于本发明所附的权利要求的保护范围。

Claims

权 利 要 求 书
1. 一种波分复用系统残余色散补偿的装置， 其特征在于， 包括性能参数 检测装置、 中心控制装置和可调色散补偿器控制装置， 其中：
所述性能参数检测装置， 用于接收并检测接收端光信号的性能参 数， 并将所述性能参数的检测结果发送到所述中心控制装置；
所述中心控制装置， 用于才艮据所述性能参数的检测结果确定可调 色散补偿器的色散调节方式， 并通过控制信令发送给所述可调色散补 偿器控制装置； 以及
所述可调色散补偿器控制装置， 用于接收所述中心控制装置发送 的控制信令， 并根据所述控制信令调节所述可调色散补偿器的色散补 偿量， 使波长通道的残余色散满足光接收器的色散容限的要求。
2. 根据权利要求 1所述的波分复用系统残余色散补偿的装置， 其特征在 于， 还包括发送端光信号控制装置， 通过数字通信网与所述中心控制 装置连接， 用于根据所述控制信令调节控制发送端光源， 使所述波长 通道的残余色散满足所述光接收器的要求。
3. 根据权利要求 1所迷的波分复用系统残余色散补偿的装置， 其特征在 于， 所述性能参数可以为接收端的误码率。
4. 根据权利要求 1所述的波分复用系统残余色散补偿的装置， 其特征在 于， 所述性能参数为所述接收端光信号的 Q值。
5. 才艮据权利要求 4所述的波分复用系统残余色散补偿的装置， 其特征在 于， 所述性能参数检测装置包括依次连接的 Q值检测装置、 通道切换 开关和分光器件， 其中：
所述 Q值检测装置， 用于检测所述接收端光信号的 Q值， 并将所 述 Q值的检测结果发送到所述中心控制装置；
所述分光器件， 设置于接收机之前， 用于从接收端光信号中分出 部分光， 并通过所述通道切换开关发送给所述 Q值检测装置； 以及 所述通道切换开关， 与所述可调色散补偿器控制装置连接， 并由 所述可调色散补偿器控制装置控制， 用于在残余色散调整过程中实现 波长通道的切换。 根据权利要求 1所述的波分复用系统残余色散补偿的装置， 其特征在 于， 所述性能参数可以为所述接收端光信号的实际光纤通道的残余色 散量。 根据权利要求 6所述的波分复用系统残余色散补偿的装置 , 其特征在 于， 所述性能参数检测装置包括依次连接的实际残余色散检测装置、 通道切换开关和分光器件， 其中：
所述实际残余色散检测装置， 用于检测所述接收端光信号的实际 光纤通道的残余色散量， 并将所述实际光纤通道的残余色散量的检测 结果发送到所述中心控制装置；
所述分光器件， 设置于接收机之前， 用于从所述接收端光信号中 分出部分光， 并通过所述通道切换开关发送给所述实际残余色散检测 装置； 以及
所述通道切换开关， 与所述可调色散补偿器控制装置连接， 并由 所述可调色散补偿器控制装置控制， 用于在残余色散调整过程中实现 波长通道的切换。 根据权利要求 6所述的波分复用系统残余色散补偿的装置， 其特征在 于， 所述性能参数检测装置包括依次连接的实际残余色散检测装置、 可调谐滤波器和分光器件， 其中：
所述实际残余色散检测装置， 用于检测所述接收端光信号的实际 光纤通道的残余色散量， 并将所述实际光纤通道的残余色散量的检测 结果发送到所述中心控制装置；
所述分光器件，用于从接收机前的复用段层分部分光并通过所述 可调谐滤波器发送给所述实际残余色散检测装置； 以及
所述可调谐滤波器， 与所述可调色散补偿器控制装置连接， 并由 所述可调色散补偿器控制装置控制， 用于在残余色散调整过程中实现 波长通道的切换。
9. 一种波分复用系统， 包括光信号发送子系统、 光信号复用段传输子系 统和光信号接收子系统， 其特征在于， 还包括波分复用系统残余色散 补偿的装置， 所述波分复用系统残余色散补偿的装置包括： 性能参数 检测装置、 中心控制装置和可调色散补偿器控制装置， 其中：
所述性能参数检测装置， 用于接收并检测接收端光信号的性能参 数， 并将所述性能参数的检测结果发送到所述中心控制装置；
所述中心控制装置， 用于根据所述性能参数的检测结果确定色散 调节方式， 并通过控制信令发送给所述可调色散补偿器控制装置； 以 及
所述可调色散朴偿器控制装置， 用于才艮据所述控制信令调节波分 复用系统接收端的可调色散补偿器的色散补偿量， 使波长通道的残余 色散满足光接收器的要求。
10. 根据权利要求 9所述的波分复用系统， 其特征在于， 所述波分复用系 统残余色散补偿的装置还包括：
发送端光信号控制装置，通过数字通信网与所述中心控制装置连 接， 用于根据所述控制信令调节控制发送端光源， 使波长通道的残余 色散满足光接收器的要求。
11. 根据权利要求 9所述的波分复用系统， 其特征在于， 所述性能参数为 所述接欠端光信号的误码率。
12. 根据权利要求 9所述的波分复用系统， 其特征在于， 所述性能参数为 所述接收端光信号的 Q值。
13. 根据权利要求 12所述的波分复用系统， 其特征在于， 所述性能参数检 测装置包括依次连接的 Q值检测装置和通道切换开关和分光器件 , 其 中：
所述 Q值检测装置， 用于检测所述接收端光信号的 Q值 , 并将所 述 Q值的检测结果发送到所述中心控制装置；
所述分光器件， 设置于接收机之前， 用于从所述接收端光信号中 分出部分光， 并通过所述通道切换开关发送给所述 Q值检测装置； 以 及 所述通道切换开关， 与所述可调色散补偿器控制装置连接， 并由 所述可调色散补偿器控制装置控制， 用于在残余色散调整过程中实现 波长通道的切换。
14. 根据权利要求 9所述的波分复用系统， 其特征在于， 所述性能参数为 所述接收端光信号的实际光纤通道的残余色散量。
15. 根据权利要求 14所述的波分复用系统， 其特征在于， 所述性能参数检 测装置包括依次连接的实际残余色散检测装置、 通道切换开关和分光 器件， 其中：
所述实际残余色散检测装置， 用于检测接收端光信号的实际光纤 通道的残余色散量， 并将所述实际光纤通道的残余色散量的检测结果 发送到所述中心控制装置；
所述分光器件， 设置于接收机之前， 用于从所述接收端光信号中 分出部分光， 并通过所述通道切换开关发送给所述实际残余色散检测 装置； 以及
所述通道切换开关， 与所述可调色散补偿器控制装置连接， 并由 所述可调色散补偿器控制装置控制， 用于在残余色散调整过程中实现 波长通道的切换。
16. 才艮据权利要求 14所述的波分复用系统， 其特征在于， 所述性能参数检 测装置包括依次连接的实际残余色散检测装置、 可调谐滤波器和分光 器件， 其中：
所述实际残余色散检测装置， 用于检测接收端光信号的实际光纤 通道的残余色散量， 并将所述实际光纤通道的残余色散量的检测结果 发送到所述中心控制装置；
所述分光器件， 用于从接收机前的复用段层分部分光并通过所述 可调谐滤波器发送给所述实际残余色散检测装置； 以及
所述可调谐滤波器， 与所述可调色散补偿器控制装置连接， 并由 所述可调色散补偿器控制装置控制， 用于在残余色散调整过程中实现 波长通道的切换。
17. 一种波分复用系统残余色散补偿的方法， 其特征在于， 包括如下步骤： 步骤 A , 性能参数检测装置接收并检测所述接收端光信号的性能 参数， 并将所述性能参数的检测结果发送到中心控制装置；
步骤 B, 所述中心控制装置根据所述性能参数的检测结果确定色 散调节方式， 并通过控制信令发送给可调色散补偿器控制装置； 以及 步骤 C, 所述可调色散补偿器控制装置根据所述控制信令调节波 分复用系统接收端的可调色散补偿器的色散补偿量， 使波长通道的残 余色散满足光接收器的要求。
18. 根据权利要求 17所述的波分复用系统残余色散补偿的方法，其特征在 于， 所述性能参数为接收端光信号的误码率、 Q值或实际光纤通道的 残余色散量。
19. 一种波分复用系统残余色散补偿的方法， 其特征在于， 包括以下步據： 步骤 A , 根据系统的通道数调节所述系统的两端波长通道的残余 色散;
步骤 B, 调节中间波长通道的残余色散； 以及
步骤 C ,根据在所述步骤 A和所述步骤 B中得到的所述两端波长通 道和所述中间波长通道的色散补偿的调节量来调节与所述两端波长通 道或所述中间波长通道相邻的通道的色散补偿量。
PCT/CN2007/000090 2006-03-10 2007-01-10 Wavelength division multiplexing system and residual dispersion compensating device and method thereof WO2007104211A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US12/282,140 US8886050B2 (en) 2006-03-10 2007-01-10 Wavelength division multiplexing system, method and device for its residual dispersion compensation
KR1020087022201A KR101295522B1 (ko) 2006-03-10 2007-01-10 파장 분할 다중 방식 시스템 및 그 잔여 분산 보상 방법과 장치
EP07702022A EP2007042A4 (en) 2006-03-10 2007-01-10 WAVE LENGTH MULTIPLEX SYSTEM AND REST DISPERSION COMPENSATING DEVICE AND METHOD THEREFOR

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN200610011478.X 2006-03-10
CNB200610011478XA CN100460902C (zh) 2006-03-10 2006-03-10 波分复用系统残余色散补偿的调节方法和装置

Publications (1)

Publication Number Publication Date
WO2007104211A1 true WO2007104211A1 (en) 2007-09-20

Family

ID=38509031

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2007/000090 WO2007104211A1 (en) 2006-03-10 2007-01-10 Wavelength division multiplexing system and residual dispersion compensating device and method thereof

Country Status (5)

Country Link
US (1) US8886050B2 (zh)
EP (1) EP2007042A4 (zh)
KR (1) KR101295522B1 (zh)
CN (1) CN100460902C (zh)
WO (1) WO2007104211A1 (zh)

Families Citing this family (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101145855B (zh) * 2007-09-27 2011-06-22 中兴通讯股份有限公司 一种光网络可调色散补偿装置及其方法
US7852152B2 (en) * 2008-08-28 2010-12-14 Menara Networks Nth order tunable low-pass continuous time filter for fiber optic receivers
CN101771473B (zh) * 2008-12-31 2013-01-16 华为技术有限公司 对光通信系统中的色散进行补偿的方法和装置
US8488962B2 (en) * 2010-05-03 2013-07-16 Verizon Patent And Licensing Inc. Bit error generation system for optical networks
CN102136866B (zh) * 2010-12-09 2014-07-30 华为技术有限公司 光传输设备和光传输系统及光传输参数配置方法
JP6031866B2 (ja) * 2012-07-20 2016-11-24 富士通株式会社 光受信装置及び特性補償方法
US9817189B2 (en) * 2013-07-01 2017-11-14 Tongqing Wang Digital dispersion compensation module
CN104158590A (zh) * 2014-08-06 2014-11-19 苏州旭创科技有限公司 光模块及具有该光模块的光纤通信系统
US10374742B2 (en) * 2017-02-15 2019-08-06 Finisar Corporation Bidirectional optical communication with minimal guard band
EP3656069A1 (en) * 2017-07-21 2020-05-27 Telefonaktiebolaget LM Ericsson (publ) Chromatic dispersion compensation
US11290184B2 (en) * 2019-03-01 2022-03-29 Molex, Llc Switchable dispersion compensating module
CN112448772B (zh) * 2019-08-29 2022-12-02 北京京东尚科信息技术有限公司 自动调节补偿参数的方法和装置
CN114556810B (zh) * 2019-10-16 2023-12-26 瑞典爱立信有限公司 控制光传输网络中色度色散的补偿
CN114362825A (zh) * 2022-01-04 2022-04-15 武汉电信器件有限公司 一种基于交换机互连的dwdm系统色散调节的方法与系统

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1479478A (zh) * 2002-07-23 2004-03-03 �ձ����ŵ绰��ʽ���� 色散监控法与设备及色散斜率温度相关性补偿法与设备
CN1518249A (zh) * 2003-01-16 2004-08-04 富士通株式会社 调节滤光设备的方法和装置
US6871024B2 (en) * 2001-01-10 2005-03-22 Fujitsu Limited Dispersion compensating method, dispersion compensating apparatus and optical transmission system
CN1674475A (zh) * 2004-03-26 2005-09-28 富士通株式会社 色散补偿方法和色散补偿装置

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4677618A (en) * 1985-04-04 1987-06-30 International Business Machines Corporation Method and apparatus for deskewing WDM data transmitted through a dispersive medium
JP3846918B2 (ja) * 1994-08-02 2006-11-15 富士通株式会社 光伝送システム、光多重伝送システム及びその周辺技術
EP0812075B1 (en) * 1996-06-07 2006-04-12 Nortel Networks Limited Optical fibre transmission systems including dispersion measurement and compensation
JPH1188260A (ja) 1997-09-09 1999-03-30 Fujitsu Ltd 光伝送路の分散補償装置
EP1104957A4 (en) * 1999-06-15 2006-06-14 Mitsubishi Electric Corp DISPERSION COMPENSATION DEVICE AND DISPERSION COMPENSATION SYSTEM
TW508920B (en) * 2000-06-01 2002-11-01 Sumitomo Electric Industries Optical transmission system
JP4592887B2 (ja) * 2000-08-07 2010-12-08 富士通株式会社 波長分散を補償する方法及びシステム
US6907197B2 (en) * 2001-03-12 2005-06-14 Nortel Networks Limited Method and apparatus for measuring and estimating optical signal to noise ratio in photonic networks
EP1347589A1 (en) * 2002-03-21 2003-09-24 Alcatel A wavelength division multiplex transmission system or a polarisation division multiplex system which means for measuring dispersion characteristics, an optical transmitter, an optical receiver and a method therefore
US7155123B2 (en) * 2002-05-10 2006-12-26 Lucent Technologies Inc. Method and apparatus for locating faults in an optical network
JP3923373B2 (ja) * 2002-05-31 2007-05-30 富士通株式会社 自動分散補償装置および補償方法
WO2004098102A1 (ja) * 2003-04-30 2004-11-11 Fujitsu Limited 光伝送ネットワーク、光伝送装置、分散補償器配置計算装置及び分散補償器配置計算方法

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6871024B2 (en) * 2001-01-10 2005-03-22 Fujitsu Limited Dispersion compensating method, dispersion compensating apparatus and optical transmission system
CN1479478A (zh) * 2002-07-23 2004-03-03 �ձ����ŵ绰��ʽ���� 色散监控法与设备及色散斜率温度相关性补偿法与设备
CN1518249A (zh) * 2003-01-16 2004-08-04 富士通株式会社 调节滤光设备的方法和装置
CN1674475A (zh) * 2004-03-26 2005-09-28 富士通株式会社 色散补偿方法和色散补偿装置

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP2007042A4 *

Also Published As

Publication number Publication date
EP2007042A4 (en) 2012-03-07
EP2007042A9 (en) 2009-07-01
KR101295522B1 (ko) 2013-08-16
US20090202248A1 (en) 2009-08-13
KR20080109753A (ko) 2008-12-17
CN101034181A (zh) 2007-09-12
CN100460902C (zh) 2009-02-11
US8886050B2 (en) 2014-11-11
EP2007042A2 (en) 2008-12-24

Similar Documents

Publication Publication Date Title
WO2007104211A1 (en) Wavelength division multiplexing system and residual dispersion compensating device and method thereof
US8131155B2 (en) Optical signal transmission apparatus
JP4011290B2 (ja) 分散補償方法、分散補償装置および光伝送システム
US9515763B2 (en) Digital coherent receiver and receiving method of optical signal
US8184978B2 (en) Method and device for channel-adapted signal transmission in optical networks
JP2006094500A (ja) 可変光分散補償および可変電子分散補償を有するイコライザ
US8712255B2 (en) Optical receiver and optical transfer apparatus
AU2005339457B2 (en) An apparatus and method for self-adaptive dispersion compensating
US8351798B2 (en) Phase shift keyed high speed signaling
US10225016B1 (en) Optical power and chromatic dispersion equalization system
JP5648436B2 (ja) プリエンファシス制御方法
WO2007071104A1 (fr) Appareil et procede de compensation de dispersion auto-adaptative
US20240056709A1 (en) Optical communication system, control apparatus and quality compensation method
WO2010050124A1 (ja) 光受信機
US20090310975A1 (en) Adaptive dispersion compensation system and method for optical communication network
JP4648363B2 (ja) 光伝送装置および光伝送装置制御方法
JP2000031904A (ja) 光分散の補償
Thiele et al. 160-Gb/s CWDM capacity upgrade using 2.5-Gb/s rated uncooled directly modulated lasers
JP4916387B2 (ja) センタ側光通信装置および光通信システム
JP5371607B2 (ja) Ｗｄｍ伝送システム
Thiele et al. WDM transmission upgrade using low-cost uncooled components
JP2012195798A (ja) 光伝送システム及び光伝送方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 07702022

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

WWE Wipo information: entry into national phase

Ref document number: 1020087022201

Country of ref document: KR

WWE Wipo information: entry into national phase

Ref document number: 3785/KOLNP/2008

Country of ref document: IN

WWE Wipo information: entry into national phase

Ref document number: 2007702022

Country of ref document: EP

WWE Wipo information: entry into national phase

Ref document number: 12282140

Country of ref document: US