Narrow-bandwidth Bragg grating filter based on Ge-Sb-Se chalcogenide glasses

Bragg grating (BG) filters play important roles in integrated photonics such as signal processing and optical sensing. In silicon-based counterpart photonic platforms, the application of narrow-bandwidth (Δλ) filters is often restrained by fabrication limitations. In this study, narrow-bandwidth BG filters based on Ge-Sb-Se chalcogenide materials are investigated. The structure of the filter is designed by optimizing the grating period, corrugation height, and grating number. The large corrugation of chalcogenide BG is more friendly and convenient for manufacturing process. The symmetric and asymmetric corrugation filters are then fabricated and characterized. Experimental results show a half-maximum bandwidth of 0.97 nm and 0.32 nm for symmetric and asymmetric filters, respectively, which demonstrates excellent narrow-bandwidth filtering performance of chalcogenide BG.