Design and analysis of a highly sensitive open trapezoidal channel PCF-based plasmonic refractometric sensor

Abstract This study introduces a highly sensitive trapezium-shaped PCF based on an SPR refractometric sensor with unique design features. The structure of a sensor was designed and analyzed using COMSOL Multiphysics v5.6 based on Finite Element Method (FEM) with a focus on investigating the influence of various geometric parameters on its performance. The two channels were coated with a metallic gold layer to provide chemical stability, and a thin layer of TiO 2 improved the gold’s adhesion to the fiber. The findings indicate that the proposed sensor achieves maximum amplitude and wavelength sensitivities of 1,779 RIU −1 and 30,500 nm RIU −1 , respectively, with corresponding resolutions of 3.28 × 10 −6 RIU for analyte RI sensing ranging from 1.30 to 1.42 operating in the visible to near-infrared region with wavelength range (500 nm–1400 nm). The highly sensitive sensor provides wide potential for RI detection in chemical and biological sensing.