Reflective Heterostructure Photonic Crystal Superprism Demultiplexer

A new design for a wideband and compact demultiplexer for coarse wavelength-division-multiplexing applications is proposed. This is based on the superprism effect, using diffraction compensation in a stratified hetero-lattice photonic crystal (PhC) operating in reflective mode. Modeling the variation of the beam envelope within the hetero-lattice, an optimum eight-channel design with 20-nm wavelength spacing is feasible within 42000 μm² of PhC area. The design results in almost diffraction-limited output beams, and provides a size reduction of 2.6 to 7 times when compared to the PhC area required in the homo-lattice SP design.