Ultra-compact and low-loss silicon polarization beam splitter using a particle-swarm-optimized counter-tapered coupler
Weiwei Chen, Bohao Zhang, Pengjun Wang, Shixun Dai, Wei Liang, Hongxiang Li, Qiang Fu, Jun Li, Yan Li, Tingge Dai, Hui Yu, Jianyi Yang
Abstract
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 µm. As the waveguide width variation ΔW 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.