Patent ID: 7231118

Claim:
A multichannel array waveguide diffraction grating multiplexer/demultiplexer comprising: an array waveguide which has cores layered on a base board and clad to cover the cores, each of the array waveguide given a predetermined curvature; an input side slab waveguide which is layered on a base board, and inputs an optical signal input through an input waveguide to the array waveguide; and an output side slab waveguide which outputs the optical signal output from the array waveguide to an output waveguide, wherein the output waveguide is given a predetermined form changed to meet the form of field distribution at a light collecting point of the output side slab waveguide, and connected to the output side slab waveguide, and a plurality of output waveguides is arranged on the arc peculiar to the output side slab waveguide, and when the output side slab waveguide is connected to the output side slab waveguide through a connecting part formed tapering or parabolic, an asymmetrical portion of the tapering or parabolic connecting part is increased as the distance from the output waveguide placed at the center on the arc with respect to the output waveguide placed at the center of the arc of the output waveguide.