Optimized hybrid plasmonic waveguide-based ring resonator for advanced refractive index sensing

Abstract

In this study, we conducted a comprehensive numerical analysis employing the finite element method (FEM) to explore the characteristics of a hybrid plasmonic waveguide (HPWG)-based ring resonator (RR) structure. Our investigation reveals that the device's sensitivity can be significantly augmented through strategic geometric modifications. The device exhibits sensitivities of approximately 176 nm/RIU and 238 nm/RIU when utilizing WG widths of 300 nm and 270 nm, respectively, in forming the ring structure. Through optimization efforts aimed at enhancing the overlap between the dielectric and plasmonic modes, the device's sensitivity reaches an optimized level of around 316 nm/RIU by reducing the ring width to 250 nm. Overall, our findings underscore the potential for leveraging geometric adjustments to enhance the sensitivity and functionality of DHPWG-based RRs, thereby advancing their utility in diverse sensing applications.