On-chip silicon 8-channel hybrid ( de) multiplexer enabling simultaneous mode-and polarization-division-multiplexing

An 8-channel hybrid (de)multiplexer to simultaneously achieve mode- and polarization-division-(de)multiplexing is proposed and demonstrated experimentally on a silicon-on-insulator platform to improve the link capacity of an on-chip optical interconnect. The present hybrid (de)multiplexer has four channels for each polarization. A polarization beam splitter based on a three-waveguide coupler is used to combine/separate the fundamental modes of TE- and TM-polarizations (TE0 and TM0). Six asymmetric directional couplers are cascaded for (de)multiplexing the high-order modes (TE1, TE2, TE3, TM1, TM2, and TM3). The experimental results show all eight channels have low loss and low crosstalk (<-10dB) over a approximate to 30nm wavelength range.