Design and Modeling of Ultra-compact and Highly-sensitive Silicon Bragg Grating Sensor for Biochemical Sensing Applications

Abstract

A silicon grating based highly sensitive nanophotonic device is proposed for biochemical sensing. Gratings are etched on the SOI rib waveguide and the dimensions of the device are optimized to enhance the sensitivity. The proposed device is a narrowband photonic filter with evanescent based Bragg gratings. The rigorous numerical analysis has been performed to evaluate the sensing capabilities of the proposed photonic biochemical sensing device. The device has been designed to operate at a wavelength of 1550 nm. The results show a high sensitivity of 770 nm/RIU with a Full Width Half Maxima (FWHM) of 7.5 nm and a figure of merit (FOM) of 103/RIU. The device is ultra-compact with a footprint area of 12.5 μm2. Further, the sensing ability for various bio-analytes has been analyzed which shows optimum performance of the proposed biochemical sensing device. © 2022, The Author(s), under exclusive licence to Springer Nature B.V.