Plasmonic Metamaterial Cloaking at Optical Frequencies

Abstract

In this paper, we present the design of cylindrical and\ud spherical electromagnetic cloaks working at visible frequencies. The cloak design is based on the employment of layered structures consisting of alternating plasmonic and nonplasmonic materials, and exhibiting the collective behavior of an effective epsilon-nearzero material at optical frequencies. The design of a cylindrical\ud cloak to hide cylindrical objects is first presented. Two alternative\ud layouts are proposed, and both magnetic and nonmagnetic objects are considered. Then, the design of spherical cloaks is also presented. The full-wave simulations presented throughout the paper\ud confirm the validity of the proposed setup, and show how this technique can be used to reduce the observability of cylindrical and spherical objects. The effect of the losses is also considered

Towards active dispersionless ENZ metamaterial for cloaking applications

“…At first, one notices that ordinary passive plasmonic cloaking (a curve with circles) is rather narrowband (this curve is quantitatively similar to the associated curve in numerical example in [20]). However, the bandwidth of active cloaking (a curve with squares) is significantly higher (one octave).…”

“…The object (target) in the original passive plasmonic cloak [1] may be a dielectric cylinder or a PEC cylinder. Here, the results for the dielectric cylinder, parameters of which (the ratio between radii of a cloak and a target of 1.8 and the relative permittivity of the target of 2) have been taken from numerical example in [20]. The cylinder was approximated with a polygon, the width of which is 27 cells, and it was simulated as a grid of 2D transmission lines.…”

“…The cylinder was approximated with a polygon, the width of which is 27 cells, and it was simulated as a grid of 2D transmission lines. The parameters of the transmission lines were chosen in order to achieve the permittivity of the target presented in [20]. The active cover was 11 cells thick and the parameters of each unit cell were derived from the measurement results of the prototyped active unit cell II at the given frequency.…”

Employment of metamaterial cloaks to enhance the resolution of near-field scanning optical microscopy systems based on aperture tips

“…silicon carbide at around 10.3 m [20]). However, the typical case is that we need to design a composite material exhibiting the required permittivity values using stacks of alternating electrically thin layers of plasmonic and non-plasmonic materials, as widely documented in [21][22][23]. Of course, when scaling the design at different wavelengths, also the values of the silver permittivity and the thicknesses of the tip change, requiring a new adjustment of the volume of the metamaterial cover, following the procedure outlined in [12].…”

Wide-Angle Polarization Independent Triple Band Absorber Based on Metamaterial Structure for Microwave Frequency Applications

“…After being inspired by Pendry et al's work [4,5], Shelby et al [6] experimentally illustrated the first lefthanded MTM in 2001 at microwave frequency regime. In last few years, MTM has been used in various electromagnetic applications, such as antenna [7], cloaking [8], filter [9] and absorber [10,11]. Nowadays, MTM based absorbers have been discussed due to their advantages of ultra-thin thickness, near unity absorption and many more, over conventional absorbers.…”