Monolithically integrated 64-channel silicon hybrid demultiplexer enabling simultaneous wavelength- and mode-division-multiplexing

A compact 64-channel hybrid demultiplexer based on silicon-on-insulator nanowires is proposed and demonstrated experimentally to enable wavelength-division-multiplexing and mode-division-multiplexing simultaneously in order to realize an ultra-large capacity on-chip optical-interconnect link. The present hybrid demultiplexer consists of a 4-channel mode multiplexer constructed with cascaded asymmetrical directional-couplers and two bi-directional 17x17 arrayed-waveguide gratings (AWGs) with 16 channels. Here each bi-directional AWG is equivalent as two identical 1x16 AWGs. The measured excess loss and the crosstalk for the monolithically integrated 64-channel hybrid demultiplexer are about -5dB and -14dB, respectively. Better performance can be achieved by minimizing the imperfections (particularly in AWGs) during the fabrication processes.