Large‐Area Low‐Cost Plasmonic Nanostructures in the NIR for Fano Resonant Sensing

Abstract

Large-area low-cost plasmonic nanostructures with high-quality Fano resonances have been fabricated for the first time. Hole-mask colloidal nanolithography is utilized and the degree of asymmetry of double split-ring resonators is varied to optimize the modulation depth of the Fano resonances for refractive index sensing. In situ optical spectroscopy during thermal annealing monitors the spectral change to control improvement of sample quality. Liquids with different refractive indices yield experimental sensitivities of up to 520 nm/RIU and figures of merit of 2.9.