Analysis of a Surface Plasmon Resonance Probe Based on Photonic Crystal Fibers for Low Refractive Index Detection

A photonic crystal fiber (PCF)-based surface plasmon resonance (SPR) probe with gold nanowires as the plasmonic material is proposed in this work. The coupling characteristics and sensing properties of the probe are numerically investigated by the finite element method. The probe is designed to detect low refractive indices between 1.27 and 1.36. The maximum spectral sensitivity and amplitude sensitivity are 6 × 103 nm/RIU and 600 RIU−1, respectively, corresponding to a resolution of 2.8 × 10−5 RIU for the overall refractive index range. Our analysis shows that the PCF-SPR probe can be used for lower refractive index detection.