Broadband and low-crosstalk polarization splitter-rotator with optimized tapers

Abstract

We proposed and experimentally demonstrated high-performance 1550- and 1310-nm silicon polarization splitter-rotators (PSRs) with optimized tapers. Each PSR consists of a particle swarm optimization (PSO)-based bi-level taper and shortcuts to an adiabaticity (STA)-based ridge-waveguide coupler. Ridge waveguides are introduced to increase the coupling coefficient of the STA-based coupler. The measured polarization conversion loss and polarization crosstalk are less than 0.74 and −20 dB, respectively, in the wavelength range of 1500–1600 nm for the 1550-nm PSR, and less than 1 and −23 dB, respectively, in the wavelength range of 1260–1340 nm for the 1310-nm PSR.