Omnidirectional cloaking based on spoof surface plasmonic structure

Abstract

Surface plasmons include surface plasmon polaritons and localized surface plasmons, which are electromagnetic wave confined at the interface of the metal and dielectric. Spoof surface plasmonic structure has many special optical properties, which is of great significance for designing new-generation optical elements. In order to transfer the features of the surface plasmon polaritons and localized surface plasmons to microwave-terahertz region, Pendry et al. (Pendry J B, Martin-Moreno L, Garcia-Vidal F J 2004 <i>Science</i> <b>305</b> 847) have proposed the spoof surface plasmon polaritons based on a metal structure with grooved stripes. In this paper, a hollow textured perfect electric conductor cylinder with periodic cut-through slits structure is designed to suppress the light scattering of the object in any direction and achieve the effect of omnidirectional cloaking while the transverse magnetic polarization wave propagates along the <i>x</i> direction. And the locations of the electrical and magnetic modes can be freely modulated by tailoring the structural geometric construction. In order to find the physical mechanism behind the abnormal phenomenon, through theoretical analysis and numerical simulation, we find that the strong scattering suppression of this spoof surface plasmonic polariton structure is caused by the interference between the background wave and Mie scattering of the structural unit, and it can be equivalent to a ring metamaterial due to the special structural design, in order to achieve the omnidirectional cloaking. It implies that we can hide objects in metal strips due to the fact that the metal in the microwave-to-terahertz region is equivalent to a perfect electrical conductor. This opens up a new way to analyzing the physical cloaking and optical response of spoof surface plasmonic polaritons structure. In addition, we also analyze the influence of the structure on the movement law of the scattering spectrum under different structural parameters. This enables us to have an in-depth understanding of the influence of structural parameters on the structural scattering spectrum. Our results can be applied to the microwave-to-terahertz region and a variety of advanced optic devices such as radars, cloaking coatings, sensors and detectors.