High contrast circular grating reflector on silicon-on-insulator platform

Abstract

A compact circular high contrast grating (HCG) reflector with a footprint of only 4.03 μm ± 4.32 μm on 220 nm silicon-on-insulator (SOI) platform is proposed and experimentally demonstrated. The proposed device breaks the high wavelength selectivity limitation for the conventional grating reflectors on a thin SOI platform by using the circular structure in a compact region. In addition, the device provides a high polarization selectivity over a wide wavelength range which is useful for applications such as tunable laser cavities and resonators to provide wide tuning range and high polarization stability. The circular structure based HCG reflector has an ultra-wide operational bandwidth (Δλ) ..