Finite wavelength cloaking by plasmonic resonance

TL;DR

This paper extends the understanding of plasmonic cloaking from quasistatic to finite wavelengths, demonstrating that cloaking remains possible but introduces non-zero scattering, influenced by material losses and geometry.

Contribution

It provides a finite wavelength analysis of plasmonic cloaking, highlighting the effects of material losses and geometric variations on scattering.

Findings

Cloaking is achievable at finite wavelengths.

Lossless materials produce monopole scattering.

Lossy materials exhibit dipole scattering.

Abstract

We consider cloaking by a coated cylindrical system using plasmonic resonance, and extend previous quasistatic treatments to include the effect of finite wavelength. We show that a probe cylinder can still be cloaked at finite wavelengths, but the cloaking cylinder develops a non-zero scattering cross-section. We show that this latter effect is dominated by a monopole term in the case of an ideal (lossless) cloaking material, and by a dipole term in the case of a realistic (lossy) material. It can be reduced but not eliminated by variations of geometric or dielectric parameters of the cloaking cylinder.