Design and Characterization of Photonic Crystal Fiber Based Surface Plasmon Resonance Refractive Index Sensor

Abstract

Photonic crystal fiber (PCF) based surface plasmon resonace sensors are very popular for detecting unknown analytes. These biosensors can detect certain range of refractive indices effectively. A spiral PCF based surface plasmon resonance sensor is proposed in this paper. Gold is used as the active plasmonic material. It is placed on the external surface of the PCF. For detection purpose, the unknown analyte flow is positioned at the outer surface of the PCF. By using the finite element method (FEM), sensing performance is analyzed. The proposed sensor shows maximum amplitude sensitivity of 997 RIU−1 and maximum wavelength sensitivity of 10,000 nm/RIU at refractive index 1.39. At the same refractive index the sensing resolution of the sensor is 1×10-5 RIU. This PCF based sensor can sense the refractive indices from 1.36 to 1.39. Furthermore, performance of the sensor is investigated by varying the value of different parameters. These are gold layer thickness, pitch and air-hole diameter. The proposed sensor can detect biological analytes for its high sensitivity, improved sensing resolution and suitable linearity.