High-FoM Resonance in Single Hybrid Plasmonic Resonator Via Electromagnetic Modal Interference

A hybrid plasmonic resonator is proposed via electromagnetic modal interference. The hybrid mode exhibits a 3.4-fold enhancement to quality factor (Q) -factor) and a 79.8-fold enhancement to figure of merit (FoM) over the original mode, breaking the common tradeoff between the Q -factor and resonance intensity. Electromagnetic simulation and temporal coupled-mode theory are used to interpret the mode evolution in the hybrid resonator structure. More importantly, this high-Q and high-FoM resonance can be excited in a single resonator unit, reducing the footprint and showing potential applications in integrated sensor chips. The sensing feasibility is demonstrated with a 4.1-fold enhancement of sensitivity and 12.8-fold enhancement of sensing FoM.