CMOS-compatible Si-wire polarization beam splitter based on wavelength-insensitive coupler

Abstract

An ultrabroadband silicon polarization beam splitter (PBS) based on a wavelength-insensitive coupler is fabricated by a standard complementary metal oxide semiconductor technology. The PBS has three identical directional couplers and two identical delay lines with a point symmetric layout. We experimentally demonstrate the broadband operation of the PBS. The crosstalk is less than −12 dB for both TE and TM modes over the wavelength range from 1532 nm to 1649 nm. Additionally, we theoretically discuss a tunability of the PBS for the first time.