Significant Propagation Loss Reduction on Silicon High-Mesa Waveguides Using Thermal Oxidation Technique

Abstract

Breath sensing system based on cavity ring-down spectroscopy (CRDS) technique is attractive due to its real time sensing in addition to the capability of high sensitivity. Utilizing waveguide for CRDS may realize ppm-order components into a compact area. This work have exploited thermal oxidation technique to silicon high-mesa waveguides for sensing-application. Significant propagation loss reduction from 1.45 to 0.84 dB/cm at a waveguide width of 500 nm has been achieved by the technique successfully.