Patent ID: 6351583
Filing Date: 2002-02-26
Classification: G02B

Abstract:
An optical apparatus for multiplexing a plurality of optical signals of different wavelengths to provide a multiplexed output optical signal, the apparatus comprising:a plurality of input waveguides for receiving the plurality of optical signals; a first free space region connected to the plurality of input waveguides; an optical grating connected to the first free space region and comprising a plurality of unequal length waveguides; a second free space region connected to the optical grating; an output waveguide connected to the second free space region for providing the multiplexed output optical signal; and first and second cross-coupling output ports connected to the second free space region for providing first and second cross-coupling output signals representative of the cross-coupling of the optical signals with said cross-coupling output signals, wherein said first and second cross-coupling signals are approximately equally strong for a given one of the optical signals only when said optical signal has a wavelength substantially equal to a specified wavelength for said optical signal.