Fano Resonances in Plasmonic Ring‐Disc‐Pair Systems

Fano resonances in plasmonic nanostructures, generated by the spectral interference between a broad resonance or continuum and narrow resonance, have attracted significant interest recent literature. Herein, introducing nanodisc next to nanoring via electron beam lithography, set of for such ring-disc-pair (RDP) hybrid is confirmed through coupling dipolar disc mode different multipolar bonding ring modes. Furthermore, influence RDP's geometric dimensions on dark-field scattering spectra experimentally studied, indicating that contrast ratio can be improved optimizing ring/disc sizes narrowing gap accordance with previous studies. The size also control locations these peaks ranging from visible near-infrared regime. In addition, comparing among series ring/split-ring/rod structures varying curvatures coupled neighboring simulations, it demonstrated RDP presents stronger sensitivity same distance shows high-quality compared more common disc-inside-ring cavities