Gold-Film-Thickness Dependent SPR Refractive Index and Temperature Sensing with Hetero-Core Optical Fiber Structure

摘要： A simple hetero-core optical ?ber (MMF-NCF-MMF) surface plasmon resonance (SPR) sensing structure was proposed. The SPR spectral sensitivity, full width of half peak (FWHM), valley depth (VD), and ?gure of merit (FOM) were de?ned to evaluate the sensing performance comprehensively. The e?ect of gold ?lm thickness on the refractive index and temperature sensing performance was studied experimentally. The optimum gold ?lm thickness was found. The maximum sensitivities for refractive index and temperature measurement were obtained to be 2933.25 nm/RIU and ?0.91973 nm/? C, respectively. The experimental results are helpful to design the SPR structure with improved sensing performance. The proposed SPR sensing structure has the advantages of simple structure, easy implementation, and good robustness, which implies a broad application prospect.