Patent ID: 6879748

Claim:
An arrayed waveguide grating, comprising: at least one input waveguide for inputting signal lights; a plurality of output waveguides for outputting said signal lights; a channel waveguide array including a plurality of waveguides, each successive waveguide of said plurality of waveguides being longer by a predetermined waveguide length difference; an input slab waveguide connecting an input end of said channel waveguide array to said at least one input waveguide; and an output slab waveguide connecting an output end of said channel waveguide array to said plurality of output waveguides, said output slab waveguide including a core layer disposed therein for propagating light therethrough, said core layer being partly cut off in selected paths therein, which interconnect said channel waveguide array and said plurality of output waveguides, and a cladding layer disposed in cut regions of said core layer and on opposite sides of said core layer, said cut regions in said selected paths including cut lengths set to predetermined values in a direction in which said signal lights propagate, depending on optical losses of said signal lights propagated in said selected paths.