Surface plasmon resonance induced methane gas sensor in hollow core anti-resonant fiber

Optical fiber sensors based on surface plasmon resonance (SPR) have been widely studied for their low cost, anti-electromagnetic interference, and remote sensing. To our best knowledge, the applications of SPR in anti-resonant optical fiber for gas sensing has not been reported before. In this study. We numerically investigated a methane gas sensor based on SPR in Hollow core anti-resonant fiber (HC-ARF) using the finite element method. Six gold films were coated on the inner wall of six anti-resonant tube in HC-ACF, while an ultraviolet-cured fluoro-siloxane nano-films containing cage molecule A were further coated on the surface of six gold films as the methane gas-sensitive film. Simulation results showed that the methane gas measurement sensitivity reached 5.54 nm/% at the methane gas concentration of 0–3.5%. Our work which greatly improves the sensitivity in SPR based optical fiber methane gas sensing can be used for the early warning of methane gas leakage.