CMOS compatible horizontal nanoplasmonic slot waveguides TE-pass polarizer on silicon-on-insulator platform

Abstract

An ultra-compact broadband TE-pass polarizer was proposed and demonstrated on the silicon-on-insulator (SOI) platform, using the horizontal nanoplasmonic slot waveguide (HNSW). Detailed design principle was presented, taking advantage of the distinct confinement region of the TE and TM modes in the HNSW. TM mode cut-off could be achieved when waveguide width was below 210 nm. Proof-of-concept devices were subsequently fabricated in a CMOS-compatible process. The optimized device had an active region length of 1 μm, three orders of magnitude smaller than similar device previously demonstrated on the SOI platform. More than 16 dB polarization extinction ratio was achieved across 80 nm wavelength range, with a relatively low insertion loss of 2.2dB. The compact device size and excellent broadband performance could provide a simple yet satisfactory solution to the polarization dependent performance drawback of the silicon photonics devices on the SOI platform.