EXCITATION LIGHT SOURCE FOR RAMAN AMPLIFICATION, RAMAN AMPLIFIER, AND OPTICAL TRANSMISSION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide an excitation light source for Raman amplification which is capable of suitably suppressing the occurrence of polarization-dependent gain.SOLUTION: An excitation light source 13 for Raman amplification includes a polarization beam splitter 16 which splits a laser beam from an excitation laser 15 into two polarization components, a polarization beam combiner 18 which combines the two polarization components, and a time difference generation part 17 provided on an optical path between the polarization beam splitter 16 and the polarization beam combiner 18. The time difference generation part 17 generates a propagation time difference between the two polarization components.