An Ag-assisted silicon slot waveguide sensor model for mid-infrared spectra gas detection with micro-ring air pressure compensation

In this paper, we introduced a metal assisted silicon slot waveguide for highly sensitive gas detection. Considering the shortage of refractive index sensing and the influence of air pressure, we choose infrared absorption as the concentration sensing mechanism instead of traditional refractive index sensing on silicon device. Because of the thin metal layer under slot waveguide, the sensitivity of sensor is significantly enhanced. Meanwhile, an air pressure detection based on refractive index sensing is realized for signal compensation, which improves the accuracy of sensor when compared with single mechanism sensor. The simulation results of designed waveguide and sensing application have shown the feasibility and improvement of this new gas sensor.