Ultra-high-power-confinement-factor integrated mid-infrared gas sensor based on the suspended slot chalcogenide glass waveguide

Abstract In this paper, we propose, design, and analyze a suspended slot chalcogenide glass waveguide gas sensor in detail. Within a bandwidth from 3.0 μm to 4.4 μm, a power confinement factor of larger than 90 % can be achieved by rationally optimizing structural parameters of the proposed waveguide sensor. When the methane is considered as the target gas, the power confinement factor, sensitivity, and limit of detection of the proposed waveguide sensor are respectively 93.81 %, 0.4578, and 18.17 ppm at a wavelength of 3.67 μm. If the operating wavelength is selected to be 3.291 μm, the power confinement factor, sensitivity, and limit of detection will be 91.98 %, 7.151, and 1.139 ppm, respectively.