Patent ID: 7330659

Claim:
An optical device for demultiplexing an input WDM signal into a plurality of output signals, the optical device comprising: a single input waveguide; a plurality of output waveguides, and a grating having a free spectral range smaller than a wavelength channel span of the input WDM signal, said grating including an input coupler, an output coupler, and an array of unequal-length waveguides connecting the input and output couplers, wherein the input and output couplers are respectively connected to the input waveguide and the plurality of output waveguides, characterized in that; upon receiving the input WDM signal at the input waveguide the optical device demultiplexes the input WDM signal into the plurality of output signals, wherein each output signal has multiple channels each one at a different wavelength, and wherein each output signal is carried by a respective plurality of in-concert output waveguides, such that each output signal is not carried by output waveguides other than its respective in-concert output waveguides.