Patent ID: 6650797
Filing Date: 2003-11-18
Classification: G02B,H04B

Abstract:
A gain equalizer for actively equalizing a gain-wavelength characteristic, comprising:polarized light separating means for separating polarized signal light into a plurality of separated polarized rays; polarization plane coincidence control means for making planes of polarization of the plurality of separated polarized rays coincident with each other, to thereby generate first polarized light; polarization variable control means for subjecting the plane of polarization of the first polarized light to rotatory control to change a ratio of a P-polarized ray to an S-polarized ray, to thereby generate polarization plane rotated light; a polarized light wavelength characteristic changing element passing the polarization plane rotated light, to thereby generate second polarized light having a wavelength characteristic corresponding to the changed ratio; polarization restoring means for subjecting the plane of polarization of the second polarized light to inverse rotatory control reverse to the rotatory control performed by said polarization variable control means on the plane of polarization of the first polarized light, to restore a polarized state identical with that of the first polarized light and thereby generate third polarized light; and polarized light synthesizing means for synthesizing the third polarized light.