Plasmonic Cloaking of Cylinders: Finite Length, Oblique Illumination and Cross-Polarization Coupling

TL;DR

This paper develops theoretical formulas and simulations for plasmonic cloaking of finite-length cylinders under various illumination conditions, demonstrating effective scattering suppression even for elongated objects and finite sizes.

Contribution

It extends plasmonic cloaking theory to finite-length cylinders with arbitrary incidence, including effects of truncation and oblique angles, validated by numerical simulations.

Findings

Single cloaking layer can suppress dominant scattering of elongated objects

Effective cloaking achieved for finite lengths comparable to wavelength

Weak dependence of cloaking performance on incidence angle

Abstract

Metamaterial cloaking has been proposed and studied in recent years following several interesting approaches. One of them, the scattering-cancellation technique, or plasmonic cloaking, exploits the plasmonic effects of suitably designed thin homogeneous metamaterial covers to drastically suppress the scattering of moderately sized objects within specific frequency ranges of interest. Besides its inherent simplicity, this technique also holds the promise of isotropic response and weak polarization dependence. Its theory has been applied extensively to symmetrical geometries and canonical 3D shapes, but its application to elongated objects has not been explored with the same level of detail. We derive here closed-form theoretical formulas for infinite cylinders under arbitrary wave incidence, and validate their performance with full-wave numerical simulations, also considering the effects of finite lengths and truncation effects in cylindrical objects. In particular, we find that a single isotropic (idealized) cloaking layer may successfully suppress the dominant scattering coefficients of moderately thin elongated objects, even for finite lengths comparable with the incident wavelength, providing a weak dependence on the incidence angle. These results may pave the way for application of plasmonic cloaking in a variety of practical scenarios of interest.