Patent ID: 6414786
Filing Date: 2002-07-02
Classification: H01S

Abstract:
An apparatus for amplifying a plurality of optical channels, each at a respective wavelength, in an optical fiber by Raman amplification comprising:a plurality of pump light sources, each of said light sources producing a pump signal of a different wavelength in consecutive order to amplify light signals propagating in said fiber, said pump signal wavelengths selected such that each pump signal is within a wavelength range of its consecutively adjacent pump signal wherein each of said pump signals experience the same polarization evolution in an optical fiber as its adjacent pump signal and wherein each pump signal is perpendicularly polarized relative to its adjacent pump signal; and a gain spectrum, associated with each of said pump signals, including a gain ripple wherein the combination of said plurality of pump signals produces a total cumulative gain spectrum with a reduced gain ripple as compared with each of said gain spectra associated with each of said pump signals.