Patent ID: 6882779

Claim:
A demultiplexer comprising: 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; an output slab waveguide connecting an output end of said channel waveguide array to said plurality of output waveguides; and means for adjusting a signal light intensity of a selected optical path by one of said plurality of output waveguides, depending on optical losses of said signal lights propagated through said selected path from said at least one input waveguide to said one of said plurality of output waveguides; and means for further adjusting an outputted signal light intensity at an output end of at least one of said plurality of output waveguides.