Refractive index sensing using surface plasmon resonance in wire-grid-enhanced hollow core fiber sensor

This paper presents a detailed analysis of a plasmonic sensor in which a plasmonic wire-grid structure is integrated into a hollow core fiber (HCF). The sensor has the capability to measure refractive indices (RIs) greater than that of the fiber material. The use of the HCF enhances the sensitivity and precision of the sensor as it allows for the efficient interaction of light with the sensing region of the wire-grid-based plasmonic structure, in comparison to a single plasmonic wire placed inside an HCF. We numerically investigate the optical properties of the sensor using the finite element method (FEM).The sensor exhibits high sensitivity, with an amplitude sensitivity of 673.97 RIU −1 , a wavelength sensitivity of 15000 nm/RIU, and a resolution of 6.67 × 10 −06 RIU, enabling precise detection of even small alterations in the RI of analyte. The sensor shows RI sensing range of 1.45 to 1.66, which is well-suited for a broad spectrum of uses, including the monitoring of biological and environmental samples.