Abstract
A novel refractive index sensor based on surface plasmon resonance (SPR) of an excentric-core photonic crystal optical fiber (PCF) is proposed, whose cladding consists of air holes of two sizes and double gold nanowires are coated on its outer surface. The air hole diameter and spacing, gold-nanowire diameter are optimized respectively to obtain the optimal sensing performance by using the finite element method (FEM). The results indicate that the proposed ex-centric core PCF-SPR sensor with the gold nanowire diameter of 0.9 µm can detect refractive index of 1.34 ~ 1.39 in the wavelength range of 600 ~ 1500 nm with the maximum wavelength sensitivity of 51200 nm/RIU, amplitude sensitivity of -1248.5 RIU− 1, minimum resolution of 1.95×10− 6 RIU and optimal FOM of 179.33 RIU− 1. The PCF-SPR has potential applications including temperature measurement, organic chemical detection, medical detection, biomolecular detection and so on.