Accessing high-order resonances in plasmonic nanostructures

Abstract

The optical excitation of high-order plasmonic resonant modes in nanostructures is important for the enhancement of light-matter interactions at the nanoscale. Due to the fast spatial variation of the electromagnetic field distribution associated with high-order modes, their excitation by conventional optical methods is extremely challenging. Here we describe a novel nonlinear scheme devised to access high-order plasmonic resonances. The proposed method is based on the temporal modulation of the permittivity of the medium surrounding a plasmonic nanoparticle. Analytical results are presented for the case of spherical nanoparticle demonstrating the effectiveness of the proposed method.