Bimodal SPR sensor in a gold-nanowire dual-core PCF

This paper presents a dual-parameter surface plasmon resonance (SPR) sensor based on what we believe to be a novel dual-core photonic crystal fiber (PCF) structure. Gold nanowires are embedded into two spatially separated detection channels. The upper channel is used for refractive index (RI) measurement, while the lower channel contains an elliptical cavity filled with trichloromethane (<i>C</i><i>H</i><i>C</i><i>l</i>₃) for temperature sensing. The influence of structural parameters on sensing performance was analyzed by the finite element method (FEM), and the parameters were optimized accordingly. For RI sensing, the proposed sensor achieves a maximum wavelength sensitivity of 30,321 nm/RIU, with a corresponding figure of merit (FOM) of 594.52<i>R</i><i>I</i><i>U</i>^-1. For temperature sensing, it operates within an environmental temperature range from 0°C to 10°C and reaches a maximum temperature sensitivity of -6.62<i>n</i><i>m</i>/^∘<i>C</i>. These features make it suitable for applications that require accurate monitoring of small temperature changes, such as quantum device temperature control, biological cold-chain logistics, and chip-scale microenvironment regulation. The proposed configuration allows simultaneous and independent detection of RI and temperature. It has a compact structure and a relatively simple fabrication process. With its high sensitivity and parallel dual-parameter capability, it shows strong potential for multi-variable monitoring in complex environments.