BENT WAVE-GUIDE COUPLERS FOR (DE)MULTIPLEXING OF ARBITRARY BROADLY-SEPARATED WAVELENGTHS USING 2-MODE INTERFERENCE

A novel technique is presented for the optimization of waveguide coupl ers configured as;broad-band wavelength (de)multiplexers. We show that bending the coupler to an appropriate radius modifies the beat length s at each wavelength, so that two-mode interference can be used to ach ieve efficient multiplexing performance with a compact device. Calcula ted and experimental results for such a device implemented in a silico n oxynitride deeply-etched rib waveguide system are presented, Almost 20-dB and 14-dB contrast are achieved in the demultiplexer configurati on at 1550-nm and 850-nm wavelengths, respectively, with a coupler onl y 145 mu m long.