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, antielectromagnetic interference, and remote sensing. To our best knowledge, the applications of SPR in antiresonant 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.