A technique for detecting hydrogen and methane using refractive index sensitivity

Hydrogen and methane, as lightweight, high-energy fuels, occupy an important position in energy utilization and industrial production, and have broad application prospects. The safe extraction and production of new energy gases, as well as the safe utilization of hydrogen and methane is increasingly essential. The problem of detecting the type and concentration of hydrogen and methane is very important. This paper proposed a multi-peak high performance metamaterial refractive index sensor to fulfill the research gap for hydrogen or methane detection. We made unique designs on the patterns of the metasurface and made innovative combinations of materials. Through discussing different shapes and geometrical parameters, we get an optimal structure with a perfect absorption state, high sensitivity, and polarization independence. In the near-infrared spectral range spanning from 1700 nm to 2600 nm, resonance peaks were observed in the absorption spectrum at wavelengths of 1738.27 nm, 1843.17 nm, and 2368.13 nm. These peaks exhibited absorption rates respectively are 99.28 %, 89.71 %, and 99.69 %. The high sensitivity of the sensor under different environmental refractive indices was up to 715.43 nm/RIU. This leads to more precise and reliable identification of hydrogen and methane. The polarization dependence of our structure ensures consistent results under light illumination from various angles. This feature enhances the convenience of using it in both production and daily life, with fewer constraints and more accurate outcomes. The possible applications of this study lie in detecting the presence of hydrogen and methane gases, the exploration and extraction of new energy gases, as well as to monitoring and alarm systems for hydrogen and methane leaks. Moreover, it can serve as a validation system for the results of hydrogen and methane production processes. These applications are of significant importance for environmental protection and process safety.