Patent ID: 6839477

Claim:
A wavelength-division-multiplexer/demultiplexer, comprising: at least one input waveguide for inputting optical signals; a grating for demultiplexing the optical signals; and, a plurality of output waveguides for outputting the optical signals demultiplexed by the grating, wherein the output waveguide comprises: a first sub-waveguide having a parabolic horn shape, in which its width is gradually decreased in a progressive direction of the optical signal, wherein said width of the first sub-waveguide is functionally dependent upon an effective wavelength of an optical signal demultiplexed to said output waveguide; and a second sub-waveguide having a straight-line shape, in which its width (W) is uniformly maintained in the progressive direction of the optical signal passing through the first sub-waveguide.