Ring gap resonant modes on disk/film coupling system caused by strong interaction

TL;DR

This paper investigates ring gap resonant modes on disk/film systems caused by strong plasmon interactions, revealing their excitation mechanisms and potential for designing advanced nanostructures.

Contribution

It introduces a hybridization method to analyze ring gap modes resulting from strong coupling between localized and continuum plasmons, validated by simulations.

Findings

Ring gap modes are excited near metallic thin films in the visible regime.

Hybridization method accurately predicts mode energies and charge distributions.

Strong coupling insights enable novel nanostructure designs.

Abstract

Peculiar ring gap modes on the surface of disk close to the metallic thin film are excited in the visible light regime. We apply plasmon hybridization method to illustrate the ring gap modes arising from the interaction between localized disk plasmons and continuum surface plasmons, which cannot be easily excited by the plane wave with polarization parallel to the film interface. In the coupled system, the hybrid modes energy and the surface charge distribution of nanoparticle are investigated both in simulation and hybridization method, showing consistence with each other. The excitation of ring gap modes provides further insight into strong coupling of the plasmon and the design of novel nanostructures.