Highly sensitive methane gas sensor based on Au/UVCFS films coated D-shaped photonic crystal fiber

Abstract In recent years, the proportion of methane explosion accidents in coal mine production accidents is increasing. The important measure to avoid methane explosion accident is to do well in methane leakage detection. Some of the surface plasmon resonance (SPR) based photonic crystal fibers (PCFs) have been proposed to achieve the methane gas sensing. However, it is difficult to fill methane gas into the inner air holes in PCFs. In order to address this issue, a D-shaped PCF methane gas sensor based on SPR was proposed and investigated based on the finite element method in this paper. A side polished air hole in the D-shaped PCF was utilized as the substrates for depositing the gold film and methane gas sensitive film. The sensing area is in direct contact with the outside methane gas. Simulation results showed that the measurement sensitivity of methane gas reached 9.88 nm/% at the methane concentration of 0%–3.5% with a linearity of 99.8%. The influence of optical structure parameters on sensor performances were also discussed. The designed sensor is expected to be a candidate for methane gas leakage detection for its simplicity and feasibility.