Fabrication-Friendly On-Chip Silicon Polarizer Based on Polarization-Selective Corner Mirrors

We propose and demonstrate a fabrication-friendly on-chip polarizer based on polarization-selective corner mirrors. The total internal reflection angles are distinct between TE and TM modes due to the strong birefringence of silicon-on-insulator (SOI) waveguide. Thus, by properly choosing the inclination angle, TE mode can be completely reflected at each corner mirror with negligible losses, whereas TM mode can be efficiently filtered out. The minimum feature size of such polarizer is as large as 400 nm. The measurement results show low excess losses of <; 1.2 dB and high extinction ratios of >20 dB over a 200-nm bandwidth. Such high performance can be maintained even with a large width deviation of > ±50 nm.