WDM transmission repeater, WDM transmission system and WDM transmission method

摘要

The present invention relates to a WDM transmission system and the like suitable for optical communications between local stations having a relatively short repeater interval. In particular, the WDM transmission repeater employed in the WDM transmission system demultiplexes a plurality of signal lights propagating through a transmission line into first and second groups, takes out the second group, comprises a multiplexer for sending into the transmission line a new WDM signal group in which the first group thus demultiplexed and a third group of signal lights different from those of the first group are multiplexed, and has a special structure for reducing the influence of the not-demultiplexed crosstalk components within the second group upon the optical communications.