HE1,1 mode-excited surface plasmon resonance for refractive index sensing by photonic crystal fibers with high sensitivity and long detection distance

As a result of the rapid development of optical fiber sensing technology, photonic crystal fiber (PCF) sensors based on surface plasmon resonance (SPR) have attracted extensive attention. To design SPR sensor with better performance, a novel ring-core PCF sensor excited by the HE 1,1 mode is proposed and demonstrated. By means of finite element method (FEM) simulation, the structure is optimized and the properties are analyzed systematically with the multi physical field analysis software COMSOL. The sensor can detect analytes with refractive indexes in the range between 1.34 and 1.425 with average sensitivity and resolution of 13,541.18 nm/RIU and 7.38 × 10 −6 RIU respectively, the longest detection distance is 556.59 m. In addition, PCF-SPR sensor has large tolerance in actual manufacturing with the low sensitivity of structural parameters and the amplitude sensitivity of all analytes is above 80 RIU −1 . This high-performance sensor has large application potential in biological sensing and oil logging.