Patent ID: 7194166

Claim:
An optical multiplexing/demultiplexing system comprising a plurality of waveguide grating couplers on a substrate and an optical port, where the plurality of waveguide grating couplers are in the same optical path as light in the optical port, and are configured to couple light between a plurality of planar waveguides on the substrate and the optical port, the optical port contains signals propagating on a plurality of wavelengths, a first subset of the plurality of waveguide grating couplers is tuned to primarily couple light to/from a first subset of the plurality of wavelengths, one of the plurality of waveguide grating couplers is tuned to primarily couple one wavelength of light from the optical port, said optical multiplexing/demultiplexing system further comprising a plurality of photodetectors, where the one wavelength of light coupled to one of the plurality of waveguide grating couplers is coupled to one of the plurality of photodetectors, and said optical multiplexing/demultiplexing system further comprising a mirror disposed on top of the one of the plurality of photodetectors, where the mirror substantially blocks incident light from impinging on top of the one photodetector.