Ultra-compact TE-pass polarizer with graphene multilayer embedded in a silicon slot waveguide.

A novel silicon slot waveguide TE-pass polarizer with graphene multilayer embedded in the slot is proposed and demonstrated by utilization of the fact that the variation of the modal characteristics for the TM mode is more than that for the TE mode. The designed polarizer is shown to have the ability to significantly suppress the transmission of the TM mode, while well guiding the TE mode. We numerically demonstrate a 7-μm-long polarizer has an ultra-high insertion loss of 31.5 dB for the TM mode and as little insertion loss as 0.2 dB for the TE mode at 1.55 μm. The presented polarizer offers the performance merits including high extinction ratio, ultra-low insertion loss, ultra-compactness, and easy integration with silicon slot waveguides without using any taper.