Optical repeater using raman amplification, wavelength division multiplexed light transmission system, excitation light supply method and excitation light control method for raman amplification

摘要

The present invention is aimed at providing an optical repeater using Raman amplification that can Raman amplify WDM signal lights propagated through a plurality of transmission systems, with high excitation efficiency and stability. To this end, an optical repeater using Raman amplification of the present invention multiplexes and demultiplexes excitation lights supplied from a plurality of excitation light sources in a star coupler and then supplies the resultant demultiplexed lights to Raman amplification media of a plurality of transmission systems via optical multiplexers, to thereby Raman amplify the WDM signal lights of the respective transmission systems. Moreover, by feedback controlling the power of each excitation light based on the result of monitoring the WDM signal light power after Raman amplification in each transmission system, a stabilized Raman amplification operation with reduced dispersion in the power of each excitation light output from the star coupler is realized.