Silicon sub-wavelength grating resonator structures for gas sensor

Abstract

Abstract This study investigates the use of silicon material as an optical waveguide for a subwavelength grating (SWG) design and micro-ring resonator structure under different conditions with CO2 as upper cladding. The CO2 was chosen to measure the sensitivity of the optical waveguide sensor, as it has a refractive index similar to air. The highest Qfactor was achieved (96.87) in the throughput port when CO2 was used as Bragg grating. The CO2 as upper cladding had a 0.4 fs time delay, considering the air as a reference spectrum. The time delay that is measured can be used to achieve higher material sensitivity. Frequency in the THz range was successfully achieved using the proposed optical waveguide sensor design and structure.