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A kind of transformation media, which we shall call the "anti-cloak", is proposed to partially defeat the cloaking effect of the invisibility cloak. An object with an outer shell of "anti-cloak" is visible to the outside if it is coated…

Optics · Physics 2009-09-29 Huanyang Chen , Xudong Luo , Hongru Ma , C. T. Chan

Acoustic invisibility of a cloaking system in turbulent uids has been poorly understood. Here we show that evident scattering would appear in turbulent wakes owing to the submergence of a classical cloaking device. The inherent mechanism is…

Fluid Dynamics · Physics 2016-11-25 Xun Huang , Siyang Zhong

Two novel classes of spherical invisibility cloaks based on nonlinear transformation have been studied. The cloaking characteristics are presented by segmenting the nonlinear transformation based spherical cloak into concentric isotropic…

Electromagnetic cloaking refers to the ability to prevent an object from scattering an incident electromagnetic field. This has been accomplished in recent works by routing the incident field around the object or by changing the scattering…

Classical Physics · Physics 2012-06-21 Michael Selvanayagam , George V. Eleftheriades

The method of coordinate transformation offers a way to realize perfect cloaks, but provides less ability to characterize the performance of a multilayered cloak in practice. Here, we propose an analytical model to predict the performance…

Optics · Physics 2009-04-30 Sheng Xi , Hongsheng Chen , Baile Zhang , Bae-Ian Wu , Jin Au Kong

There is currently a great deal of interest in the invisibility cloaks recently proposed by Pendry et al. that are based in the transformation approach. They obtained their results using first order transformations. In recent papers Hendi…

Optics · Physics 2009-11-13 Ricardo Weder

Recently, invisible cloaks have attracted much attention due to their exciting property of invisibility, which are based on a solid theory of transformation optics and quasi-conformal mapping. Two kinds of cloaks have been proposed:…

Optics · Physics 2015-05-14 Hui Feng Ma , Wei Xiang Jiang , Xin Mi Yang , Xiao Yang Zhou , Tie Jun Cui

We derive and discuss general physical bounds on the electromagnetic scattering and absorption of passive structures. Our theory, based on passivity and power conservation, quantifies the minimum and maximum allowed scattering for an object…

Optics · Physics 2015-06-17 Romain Fleury , Jason Soric , Andrea Alu

The suggestive idea of "cloaking" an electromagnetic sensor, i.e., strongly reducing its visibility (scattering) while maintaining its field-sensing (absorption) capabilities, has recently been proposed in the literature, based on…

We experimentally demonstrated an alternative approach of invisibility cloaking that can combine technical advantages of all current major cloaking strategies in a unified manner and thus can solve bottlenecks of individual strategies. A…

The effect of electrostatic shielding for a spherical invisibility cloak with arbitrary charges inside is investigated. Our result reveals that the charge inside the cloak is a crucial factor to determine the detection. When charged bodies…

Optics · Physics 2012-11-28 Ruo-Yang Zhang , Qing Zhao , Mo-Lin Ge

We demonstrate three simple cloaking devices that can hide very large spatial objects over the entire visible spectrum using only passive, off-the-shelf optics. The cloaked region for all of the devices exceeds 10^6 mm3 with the largest…

Optics · Physics 2015-06-16 John C. Howell , J. Benjamin Howell

In this Letter we develop analytical formulations to describe sound scattering in lossless medium due to 2D circular wave incident on an acoustic cloak. A perfect acoustic cloak is reflectionless and can completely hide the cloaked object…

Classical Physics · Physics 2012-05-08 Siyang Zhong , Xun Huang

It is generally believed that transformation optics based cloaking, besides rendering the cloaked region invisible to detection by scattering of incident waves, also shields the region from those same waves. We demonstrate a coupling…

Optics · Physics 2016-05-13 Allan Greenleaf , Yaroslav Kurylev , Matti Lassas , Gunther Uhlmann

The aim of this paper is to extend the method of improving cloaking structures in the conductivity to scattering problems. We construct very effective near-cloaking structures for the scattering problem at a fixed frequency. These new…

Analysis of PDEs · Mathematics 2015-05-30 Habib Ammari , Hyeonbae Kang , Hyundae Lee , Mikyoung Lim

This note is a comment on a recent article [Tsakmakidis, et al., Nat Commun 10 (2019)] that presents a thought-provoking proposal to overcome the bandwidth restrictions of invisibility cloaks based on using media that support superluminal…

We design non-singular cloaks enabling objects to scatter waves like objects with smaller size and very different shapes. We consider the Schrodinger equation which is valid e.g. in the contexts of geometrical and quantum optics. More…

Mathematical Physics · Physics 2010-12-07 Andre Diatta , Sebastien Guenneau

Acoustic cloaks that make object undetectable to sound waves have potential applications in a variety of scenarios and have received increasing interests recently. However, the experimental realization of a three-dimensional (3D) acoustic…

Classical Physics · Physics 2014-03-13 Weiwei Kan , Bin Liang , Ruiqi Li , Xue Jiang , Xin-ye Zou , Lei-lei Yin , Jianchun Cheng

We show that dielectric or even perfectly conducting cylinders can be cloaked by a uniform or a layered dielectric cladding, without the need of any exotic or magnetic material parameters. In particular, we start by presenting a simple…

Classical Physics · Physics 2015-06-03 Constantinos A. Valagiannopoulos , Pekka Alitalo

Recent research has uncovered a remarkable ability to manipulate and control electromagnetic fields to produce effects such as perfect imaging and spatial cloaking. To achieve spatial cloaking, the index of refraction is manipulated to flow…