Optical Fiber Refractive Index Sensor Based on the SPR Using a Multiple D-shaped Ag Nanowire

Abstract

This study proposes the simulation of multiple D-shaped Ag nanowires (AgNWs) based on a highly sensitive surface plasmon resonance (SPR) optical fiber external refractive index (RI) sensor. The effect of SPR on the core-guided and plasmon modes of the designed multiple D-shaped AgNWs was used to clarify the changes in the external RI. The influencing parameters of the proposed sensor, such as the amount of residual cladding (D) and radius of the AgNW (r a ), were optimized using the method of finite element (FEM) on the basis multiphysics of COMSOL. Simulation results verify that the maximum sensitivity of the SPR fiber sensor is 5.1 μm/RIU in the external RI range of 1.35 - 1.39, with 0.4 μm residual cladding (D) and 60 nm radius of the AgNW (r a ). The results manifested the potential of the proposed SPR sensor-based multiple D-shaped AgNW structure of the biosensor applications.