An investigation on the effects of geometrical parameters on the sensitivity of micro-disk and micro-ring plasmonic sensors

Abstract

Geometrical parameters of coupled plasmonic resonators that consist of micro-disk and micro-ring structures have been investigated numerically, and changes in the Q factor, mode volume, and Purcell coefficient of the investigated structure have been calculated according to changes in geometrical variables. Optimal geometrical values for achieving plasmonic modes have been found using simulation results. Additionally, the performance of a single micro-disk, the single micro-ring, and two coupled micro-ring structures as a refractive index sensor has been compared and reported. It has also been shown that although the general shape of the figure of merit (FoM) graph is the same for all tested structures, the FoM of the disk resonator achieves lower values compared to ring and coupled resonators.