Low-Loss Broadband Silicon TM-Pass Polarizer Based on Periodically Structured Waveguides

A compact and high performance integrated silicon TM-pass polarizer is proposed and experimentally demonstrated. The device is formed by periodically structuring a waveguide with a slot section within each period, and is implemented on a silicon-on-insulator platform. The fabricated device has low insertion loss for the TM mode (average 0.7dB) and high extinction for the TE mode (average 41.25dB), over a 1.5 \mu \text{m} to 1.6 \mu \text{m} wavelength range. Numerical simulations indicate that a large fraction of the blocked TE mode radiates out of the periodic structure, resulting in weak back reflections. The compact footprint of the device (21 \mu \text{m}\,\,\times 0.5 \mu \text{m} ) makes it suitable for dense integration in photonic integrated circuits.