Vertical cavity waveguide spectrometer for WDM communication

There is currently a need for a high resolution, low cost optical wavelength demultiplexer for wavelength division multiplexing (WDM) systems. Bulk grating and mechanical Fabry-Perot interferometers have been inappropriate for many WDM switching applications. Consequently, there have been many efforts to achieve a monolithic solution, generally using a diffraction grating written on planar waveguides. However, fabrication difficulties have precluded a simple low cost device. We describe a novel approach for wavelength demultiplexing using a Fabry-Perot resonator fabrication parallel to the input waveguide. Since the device requires only thin film technology and no diffraction grating, we expect lower cost and simpler implementation.