Patent ID: 6785042
Filing Date: 2004-08-31
Classification: H01S,H04B

Abstract:
A slope control method of gain wavelength characteristics of Raman amplification, for controlling wavelength characteristics of optical transmission powers caused in wavelength division multiplexed signal light transmitted through an optical transmission path, the method comprising:a Raman amplification generating step for supplying Raman pump lights of a plurality of wavelength band sets corresponding to linear wavelength characteristics of optical transmission powers, to a Raman amplifying medium forming at least a part of said optical transmission path, so as to generate Raman amplification having gain wavelength characteristics capable of compensating said linear wavelength characteristics of optical transmission powers, for wavelength division multiplexed signal light propagated through said Raman amplifying medium, said gain wavelength characteristics of Raman amplification being such that gain wavelength characteristics corresponding to Raman pump lights of at least one set of said wavelength band sets among said Raman pump lights of the plurality of wavelength band sets has slope characteristics in linearly opposite directions in a signal light band; a wavelength characteristic monitoring step for monitoring wavelength characteristics of optical transmission powers, for wavelength division multiplexed signal light passed through said Raman amplifying medium; and a Raman amplification controlling step for adjusting proportions of said Raman pump lights of at least one set of said wavelength band sets based on a result of said wavelength characteristic monitoring step, to thereby control the gain wavelength characteristics of Raman amplification such that said wavelength characteristics of optical transmission powers are flattened.