Dual-Channel and Dual-Core Plasmonic Sensor–Based Photonic Crystal Fiber for Refractive Index Sensing

A dual-core photonic crystal fiber (PCF) with dual-channel-based surface plasmon resonance (SPR) sensor is designed. The silver and gold films are severally coated in the inner walls of two large ring detection channels to excite the plasmon modes, which can make the designed sensor achieve the dual-channel sensing. The effect of structure parameters on the sensing properties and loss spectrum is numerically analyzed by finite element method (FEM). When the analyte refractive index (RI) changes from 1.340 to 1.360, the average spectral sensitivities of 4280 and 3940 nm/RIU are obtained for the left and right channels, corresponding to the RI resolutions of 2.34 × 10−5 and 2.54 × 10−5 RIU, respectively. The simulation results suggest that the designed dual-channel sensor can realize highly sensitive detection of two analytes simultaneously, which has a wide application in the fields of biomedical analysis and environmental monitoring.