Dynamic gain equalizer

Abstract

The present invention provides a dynamic gain equalizer for flattening a gain profile of an optical amplifier. The dynamic gain equalizer includes: an optical waveguide circuit 2 having: a multistage optical coupler 7 which is formed by connecting optical couplers 1 arranged at a plurality of stages; a multistage optical coupler 11 formed by connecting optical couplers 3 arranged at a plurality of stages; and optical connecting circuits 12 including optical phase shifters 9 each capable of changing a phase of propagating light and optical delay lines 10 each for adding a predetermined delay time to the propagating light, said dynamic gain equalizer in which at least one of the optical couplers 1 in the multistage optical coupler 7 and at least one of the optical couplers 3 in the multistage optical coupler 11 are provided with variable optical amplitude means 21 and 22, respectively, and the multistage optical coupler 7 and the multistage optical coupler 11 are formed asymmetrically with respect to an extension of a line which connects a center arranged position of optical outputting ends 17 of the multistage optical coupler 7 with a center arranged position of optical inputting ends 18 of the multistage optical coupler 11.

Dependencies are inferred from the claim text.