A Novel Plasmonic Sensor Based on Dual-Channel D-Shaped Photonic Crystal Fiber for Enhanced Sensitivity in Simultaneous Detection of Different Analytes.

A dual-channel D-shaped photonic crystal fiber (PCF) based plasmonic sensor is proposed in this paper for the simultaneous detection of two different analytes using the surface plasmon resonance (SPR) technique. The sensor employs a 50 nm-thick layer of chemically stable gold on both cleaved surfaces of the PCF to induce the SPR effect. This configuration offers superior sensitivity and rapid response, making it highly effective for sensing applications. Numerical investigations are conducted using the finite element method (FEM). After optimizing the structural parameters, the sensor exhibits a maximum wavelength sensitivity of 10000 nm/RIU and an amplitude sensitivity of -216 RIU between the two channels. Additionally, each channel of the sensor exhibits its unique maximal wavelength and amplitude sensitivities for different refractive index (RI) ranges. Both channels demonstrate a maximal wavelength sensitivity of 6000 nm/RIU. In the RI range of 1.31-1.41, Channel 1 (Ch1) and Channel 2 (Ch2) achieved their maximum amplitude sensitivities of -85.39RIU and -304.52 RIU , respectively, with a resolution of 5×10 . This sensor structure is noteworthy for its ability to measure both amplitude and wavelength sensitivity, providing enhanced performance characteristics suitable for various sensing purposes in chemical, biomedical, and industrial fields.