Plasmon-Induced Concentric Hexagonal Ring Resonator for Nanophotonic Sensing

A metal-insulator-metal waveguide-based concentric hexagonal ring resonator plasmonic nanosensor has been designed and optimized for sensing the refractive index of analytes. The sensor has been functionalized through a wide range of midIR wavelengths. In the spectral output from the sensor, the prevalent plasmonic modes (dipolar and quadrupolar) have exhibited prominent shifts in the resonance wavelengths with the changes as slight as 0.00025 RIU in the refractive index of the surrounding medium, making promises as a refractive index sensor. Further explorations have shown a systematic linear correlation of the resonance wavelengths with the refractive indices, with a sensitivity as high as 2700nm/RIU and a figure of merit ~17.5.