A Compact High Sensitive D Shape Surface Plasmon Sensor

Abstract

In this paper, we numerically design a refractive index-based surface plasmon fiber sensor by exploiting the optical characteristics of a commercially available side polished D-shaped photonic crystal fiber (PCF) using finite element method. The proposed sensor could work in the infrared regime for a wide range of analytes with refractive indices ranging from 1.33 to 1.36. The proposed sensor exhibits a maximum sensitivity of 31,800 nm/RIU with a resolution of 3.14×10^-6 RIU when the refractive index is varied from 1.355 to 1.36. Further, considering the practical implementation, we carry out the fabrication tolerance of ± 5% of the proposed sensor by varying the optimized structural parameters. Based on the numerical results, we find that the proposed sensor is highly robust against the variations in the structural parameters. As the proposed fiber sensor has a strong surface plasmon resonance between the core mode and the surface plasmon mode, it is highly sensitive even for a minimum change in the refractive index of the analyte which is an attribute of high preference in biosensors.