Wavelength division multiplexing system, method and device for its residual dispersion compensation

A wavelength division multiplexing system, comprising an optical signal sending subsystem, an optical signal multiplexing section transmission subsystem and an optical signal receiving subsystem, characterized in, further comprising a device for residual dispersion compensation of wavelength division multiplexing system, which comprises a performance parameter detecting device, a central control device and a tunable dispersion compensator control device, wherein the performance parameter detecting device is used for receiving and detecting a performance parameter of a receiving terminal optical signal, wherein the optical signal includes a highest wavelength channel and a lowest wavelength channel, and sending a detecting result of the performance parameter to the central control device, wherein the detecting result is the performance parameters for only the highest and the lowest wavelength channels;

• the central control device is used for deciding a dispersion adjusting mode of first and second tunable dispersion compensators according to the detecting result of the performance parameter and sending the dispersion adjusting mode to the tunable dispersion compensator control device through control signaling;
• and
• the tunable dispersion compensator control device is used for adjusting dispersion compensation amounts of the first and second tunable dispersion compensators of a receiving terminal of wavelength division multiplexing system according to the control signaling to make residual dispersion of the highest and lowest wavelength channels satisfy requirements of dispersion tolerance of corresponding first and second optical receivers;
• wherein the dispersion compensation amount of the first and second tunable dispersion compensators, when the residual dispersion of the highest and lowest wavelength channels satisfies the requirements of dispersion tolerance of the first and second optical receivers, is used to adjust dispersion compensation amount of a third tunable dispersion compensator of an adjacent wavelength channel having a wavelength greater than the lowest wavelength channel and less than the highest wavelength channel to satisfy a requirement of dispersion tolerance of a third optical receiver.

A method of residual dispersion compensation of wavelength division multiplexing system, characterized in, comprising the following steps:

• Step A:
• a performance parameter detecting device receiving and detecting a performance parameter of a receiving terminal optical signal, wherein the optical signal includes a highest wavelength channel and a lowest wavelength channel, and sends a detecting result of the performance parameter to a central control device, wherein the detecting result is the performance parameters for only the highest and the lowest wavelength channels;
• Step B:
• the central control device deciding a dispersion regulating mode of first and second tunable dispersion compensators according to detecting result of the performance parameter and sending the dispersion regulating mode to a tunable dispersion compensator control device through control signaling;
• Step C:
• the tunable dispersion compensator control device adjusting dispersion compensation amounts of the first and second tunable dispersion compensators of a receiving terminal of wavelength division multiplexing system according to the control signaling to make residual dispersion of the highest and lowest wavelength channels satisfy requirements of dispersion tolerance of corresponding first and second optical receivers;
• wherein the dispersion compensation amount of the first and second tunable dispersion compensators, when the residual dispersion of the highest and lowest wavelength channels satisfies the requirements of dispersion tolerance of the first and second optical receivers, is used to adjust dispersion compensation amount of a third tunable dispersion compensator of an adjacent wavelength channel having a wavelength greater than the lowest wavelength channel and less than the highest wavelength channel to satisfy a requirement of dispersion tolerance of a third optical receiver.