Tapered Fabry-Perot Waveguide Optical Demultiplexer

We describe a novel waveguide spectrometer for use in wavelength division multiplexing (WDM) systems. A high refractive index resonator is coupled to a waveguide and extracts light from the waveguide at its resonance frequency. A taper in the thickness of the resonator allows light of different wavelengths to be extracted at different positions. A structure is fabricated for use at 750 nm with a measured dispersion of 29 nm/cm and a wavelength resolution of 1 nm. The device operation is in good agreement with first-order coupled-mode calculations. © 1993 IEEE