A highly sensitive dual-core D-Shape photonic crystal fiber based on surface plasmon resonance for methane sensing

Abstract

This paper presents a gas sensor that uses surface plasmon resonance (SPR) technology and a novel D-type photonic crystal fiber (PCF) structure to detect methane. The sensor's double-sided, side-polished gas holes are the key components for achieving large-area contact with external methane gas. The coating material chosen to stimulate the SPR effect was a gold nanolayer. To increase the sensitivity of methane gas detection, the researchers used polysiloxane-doped cryptane E as a coating material. The study analyzed the sensor characteristics using finite element analysis (FEA) and numerical analysis to examine the effect of optical structure parameters on the sensor performance. The numerical results demonstrate that the sensor has a sensitivity of 11.52 nm/% and a FOM value of 0.409 when measuring methane gas in the concentration range of 0–3.5%. The curve fitted shows excellent linearity. The sensor is a promising technology for the future development of gas leakage detection due to its low cost, simplicity, and real-time detection capability.