D-shaped Photonic Crystal Fiber Based on Surface Plasmon Resonance Sensor with Metal Nanodimers Array

A D-shaped photonic crystal fiber (PCF) sensor with metal nanodimers array is presented and demonstrated for analyte detection with refractive index (RI) ranging from 1.28 to 1.37. In contrast to previous D-shaped PCF sensors, the coupling system is composed of Au-Ag nanodimers array, Silver (Ag) nanowires are arranged under the Gold (Au) array on the D-shaped surface, which cause the electric field within a confined volume is strongly enhanced, and the sensitivity of the surface plasmon resonance to dielectric environment of this volume to be promoted by near-field coupling. The finite element method (FEM) is adopted to numerical investigate the coupling characteristics and sensing performance of the PCF sensor in the near-infrared region. An average wavelength sensitivity (WS) of 14021 nm/RIU is attained,and a maximum WS of 16380 nm/RIU is acquired with a supernal RI resolution of 6.11×10 -6 RIU, which has an excellent application prospect in the fields of biological, biochemical and environmental detection.