An ultracompact hybrid plasmonic waveguide polarization beam splitter

摘要

We propose an ultracompact polarization beam splitter based on an asymmetric directional coupler, which comprises of a horizontally slotted waveguide and a hybrid plasmonic waveguide. The splitter is designed such that there is a large difference between the effective indices of the TE-polarized modes for the two waveguides, while the effective index difference between the TM-polarized modes are quite small in a wide wavelength range. Numerical results demonstrate that the proposed splitter with a short device length of 5 μm shows extinction ratios as low as -20 dB with bandwidths as great as 100 nm.