Ultra-compact and low-loss silicon polarization beam splitter using a particle-swarm-optimized counter-tapered coupler

In this paper, an on-chip silicon polarization beam splitter using a particle-swarm-optimized counter-tapered directional coupler is proposed, designed, and fabricated. The coupling length of the proposed device is only 5 mu m. As the waveguide width variation Delta W increases from 20 to 20 nm, the simulated polarization extinction ratio larger than 18.67 dB and the corresponding insertion loss lower than 0.17 dB are achieved. Measured experimental results achieved insertion loss < 0.50 dB, TE polarization extinction between 16.68 to 31.87 dB, TM polarization extinction between 17.78 to 31.13 dB, over the wavelength range 1525 to 1600 nm. (C) 2020 Optical Society of America under the terms of the OSA Open Access Publishing Agreement