On-Chip Silicon TE-Pass Polarizer Based on Asymmetrical Directional Couplers

An on-chip silicon TE-pass polarizer is proposed and demonstrated. The proposed polarizer is realized by asymmetrical directional couplers assisted with sharp bending and tapered waveguides. The TM0mode is converted into TM1mode through the asymmetrical directional coupler and then filtered out by the bending and taper, while TE0mode goes through with negligible coupling due to the phase mismatch. The measured extinction ratio at central wavelength is 29.8 dB, while the -15 dB bandwidth is >80 nm.