Compact 10-channel mode division (de)multiplexer based on collateral asymmetric directional couplers

Abstract

A compact 10-channel mode (de)multiplexer based on mode- and polarization-division multiplexing is designed to improve the transmission capacity of the on-chip optical interconnects. This presented hybrid (de)multiplexer consists of three cascaded coupling sections where each section includes two or four collateral asymmetric directional couplers to drop the high-order modes (TM1~TM3 and TE1~TE5) as the fundamental mode. A polarization beam splitter is designed to combine/separate TM0 and TE0 mode. The directional couplers are collocated in the configuration so that the overall coupling length for the (de)multiplexing device is only 59.3 µm. The simulations show that the device has low insertion loss (<0.99 dB) and low crosstalk (<−15.6 dB) within a wavelength range of ~35 nm.