OPTICAL TRANSMISSION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide an optical transmission system which is capable of obtaining high frequency utilization efficiency and suppresses transmission quality deterioration caused by XPM between optical signals of different modulation modes mixed in the same optical fiber transmission line.SOLUTION: The optical transmission system uses together two single-core bidirectional transmission systems in which double-core fiber transmission lines are used and optical signals in two directions of uplink and downlink directions are accommodated in one optical fiber transmission line. A wavelength arrangement is configured in such a manner that the modulation mode of optical signals accommodated in a downlink direction of one optical transmission line in the two systems is only a first modulation mode and that the modulation mode of optical signals accommodated in an uplink direction is only a second modulation mode. The wavelength arrangement is configured in such a manner that the modulation mode of optical signals accommodated in a downlink direction of the other optical transmission line in the two systems is only the second modulation mode and that the modulation mode of optical signals accommodated in an uplink direction is only the first modulation mode.