Integrated optical wavelength demultiplexer (iowd)

Abstract From the Canadian patent

Abstract of the Disclosure, An integrated optical wavelength demultiplexer has deposited on a waveguide layer a pair of Luneburg lenses, the first for collimating light from an optical fiber, the second for focussing light at an array of photodetectors formed under the waveguide layer. Between the lenses is the dispersive element, a thin-film prism of a highly dispersive low-loss material such as arsenic trisulfide. A known integrated optical demultiplexer which uses a chirped, diffraction grating to spatially disperse (rather than angularly disperse) the optical wavelengths would suffer a, greater insertion loss particularly for wavelengths coupled out at a later point in the grating. …