Analysis of electromagnetic scattering from plasmonic inclusions beyond the quasi-static approximation and applications

TL;DR

This paper analyzes electromagnetic scattering from plasmonic inclusions beyond the quasi-static approximation, deriving eigensystems and constructing structures for resonance and cloaking, with potential applications in imaging.

Contribution

It introduces a full Maxwell system analysis for plasmonic inclusions, deriving eigensystems and designing structures for resonance and cloaking beyond existing methods.

Findings

Complete eigensystem of integral operator derived for spherical geometry

Construction of plasmonic structures inducing surface resonances

Discovery of a new cloaking phenomenon different from previous ones

Abstract

This paper is concerned with the analysis of time-harmonic electromagnetic scattering from plasmonic inclusions in the finite frequency regime beyond the quasi-static approximation. The electric permittivity and magnetic permeability in the inclusions are allowed to be negative-valued. Using layer potential techniques for the full Maxwell system, the scattering problem is reformulated into a system of integral equations. We derive the complete eigensystem of the involved matrix-valued integral operator within spherical geometry. As applications, we construct two types of plasmonic structures such that one can induce surface plasmon resonances within finite frequencies and the other one can produce invisibility cloaking. It is particularly noted that the cloaking effect is a newly found phenomenon and is of different nature from those existing ones for plasmonic structures in the literature. The surface plasmon resonance result may find applications in electromagnetic imaging.