Surface plasmon resonance sensor based on a dual-hole optical fiber for temperature and refractive index detection

This paper presents a surface plasmon resonance (SPR) sensor based on a dual-hole optical fiber, designed for the simultaneous measurement of refractive index (RI) and temperature. The sensor is fabricated by side-polishing the dual-hole fiber and coating gold and silver films in the left and right holes, respectively. Additionally, the right hole is filled with polydimethylsiloxane to enable dual-parameter detection. We analyzed the sensor's performance using the finite element analysis software COMSOL, and the results indicate a peak sensitivity reaching 3000 nm/RIU across an RI interval of 1.34-1.38, along with a temperature sensitivity measured at -4.5nm/^∘C within a range spanning from 0°C to 40°C. The proposed dual-hole fiber SPR sensor features a simple structure and demonstrates high sensitivity and effective dual-parameter sensing capabilities. This provides an efficient solution for the simultaneous monitoring of temperature and RI, making it suitable for in situ measurements in applications such as chemical reagent preparation.