Dual Peak Double Resonance Sensing Using a Dual Plasmonic Material PCF-SPR Sensor

A sensor with plasmonic materials gallium doped zinc oxide (GZO) and gold has been designed and analyzed numerically in this paper that utilizes localized surface plasmon resonance (LSPR) technology. Combination of the simultaneous use of two plasmonic material has resulted in a unique dispersion relation that exhibits double resonance peaks at two distinct wavelengths. A novel parameter, Double Peak Shift Sensitivity (DPSS), that takes the effect of double resonant peak into account, has been used to enhance the structural parameters of the introduced sensor. Upon optimizing the structural parameters using COMSOL Multiphysics simulation, it was observed that the sensor shows maximum DPSS of 11,720 um/RIU. Furthermore, the proposed sensor demonstrates a wide analyte detection scope from refractive indices 1.30 to 1.40. The sensor can detect analytes with wavelengths between 0.3 and 0.98 um, which includes both ultraviolet and visible light spectrum. Besides, a high wavelength sensitivity of 11,480 nm/RIU was reported for analyte RI change from 1.39 to 1.40 and corresponding resolution was found to be 8.71 x 10(-6) RIU. Moreover, the sensor exhibited very low confinement losses which is suitable for longer sensor lengths. The unique characteristic of sensing in both ultraviolet (UV) and visible light range of the proffered design can pave the way for significant advancements in biosensing applications with extremely high accuracy and a broad range of applications.