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In the past years quasi-conformal mapping has been typically used to design broadband electromagnetic cloaks. However, this technique has some inherit practical limitations such as the lateral beam shift, rendering the device visible or…

Optics · Physics 2013-11-25 Yungui Ma , Yichao Liu , Lu Lan , Tiantian Wu , Wei Jiang , C. K. Ong , Sailing He

We develop an optimization framework for the design of acoustic cloaks, with the aim of overcoming the limitations of usual transformation-based cloaks in terms of microstructure complexity and shape arbitrarity of the obstacle. This is…

Optimization and Control · Mathematics 2022-02-16 Sebastiano Cominelli , Davide Enrico Quadrelli , Carlo Sinigaglia , Francesco Braghin

In this contribution, we present the design of cylindrical electromagnetic cloaks working at optical frequencies, making use of layered structures of plasmonic and non-plasmonic materials. The simulated results confirm the validity of the…

Optics · Physics 2008-06-09 F. Bilotti , S. Tricarico , L. Vegni

The key challenge in current research into electromagnetic cloaking is to achieve invisibility over an extended bandwidth. There has been significant progress towards this using the idea of cloaking by sweeping under the carpet of Li and…

The fully covariant formulation of transformation optics is used to find the configuration of a cloaking device operating in an expanding universe modelled by a Friedmann-Lema\^itre-Robertson-Walker spacetime. This spacetime cloak is used…

Optics · Physics 2015-07-23 Robert T. Thompson , Mohsen Fathi

Based on the concept of complementary media, we propose an invisibility cloak operating at a finite frequency that can cloak an object with a pre-specified shape and size within a certain distance outside the shell. The cloak comprises of a…

Optics · Physics 2009-11-13 Yun Lai , Huanyang Chen , Zhao-Qing Zhang , C. T. Chan

We show that the optical properties of an oblique layered system with two kinds of isotropic materials can be described using the concept of transformation media as long as the thickness of the layers is much smaller than the wavelength.…

Optics · Physics 2008-08-28 Huanyang Chen , C. T. Chan

We make precise some results on the cloaking of displacement fields in linear elasticity. In the spirit of transformation media theory, the transformed governing equations in Cosserat and Willis frameworks are shown to be equivalent to…

Analysis of PDEs · Mathematics 2019-04-08 Richard Craster , Andre Diatta , Sebastien Guenneau , Harsha Hutridurga

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 present a novel approach of modelling surface light scattering in the context of freeform optical design. The model relies on energy conservation and optimal transport theory. For isotropic scattering in cylindrically or rotationally…

A central ingredient of cloaking-by-mapping is the diffeomorphisn which transforms an annulus with a small hole into an annulus with a finite size hole, while being the identity on the outer boundary of the annulus. The resulting…

Analysis of PDEs · Mathematics 2021-09-07 Yves Capdeboscq , Michael Vogelius

We consider an ideal invisibility cloak which is illuminated by monochromatic light and which moves in vacuum at constant relativistic velocity with respect to the common inertial frame of light source and observer. We show that, in…

Optics · Physics 2016-02-03 Jad C. Halimeh , Robert T. Thompson , Martin Wegener

In [AIP Advances 6, 121707 (2016)], a soil structured with concrete columns distributed within two specially designed seismic cloaks thanks to a combination of transformational elastodynamics and effective medium theory was shown to detour…

Classical Physics · Physics 2018-02-06 Andre Diatta , Younes Achaoui , Sebastien Guenneau

In this paper, we use the parameter retrieval method together with an analytical effective medium approach to design a well-performed invisible cloak, which is based on an empirical revised version of the reduced cloak. The designed cloak…

Optics · Physics 2011-05-10 Yangbo Xie , Huanyang Chen , Yadong Xu , Lin Zhu , Hongru Ma , Jian-Wen Dong

We consider reshaping a scattering obstacle virtually by using transformation optics in acoustic and electromagnetic scattering. Among the general virtual reshaping results, the virtual minification and virtual magnification are…

Optics · Physics 2009-11-13 Hongyu Liu

Cloaking is typically reciprocal. We introduce here the concept of \emph{transmittable nonreciprocal cloaking} whereby the cloaking system operates as a standard omnidirectional cloak for external illumination, but can transmit light from…

Applied Physics · Physics 2022-12-08 Mojtaba Dehmollaian , Guillaume Lavigne , Christophe Caloz

Semantic segmentation for robotic systems can enable a wide range of applications, from self-driving cars and augmented reality systems to domestic robots. We argue that a spherical representation is a natural one for egocentric…

Robotics · Computer Science 2022-10-26 Lukas Bernreiter , Lionel Ott , Roland Siegwart , Cesar Cadena

Recently, it was shown that an infinite perfectly conducting (PEC) cylinder can be nearly perfectly cloaked from normally incident electromagnetic waves using a single-layer homogeneous dielectric cladding. Here we study the electromagnetic…

Mathematical Physics · Physics 2012-11-26 Constantinos A. Valagiannopoulos , Pekka Alitalo , Sergei A. Tretyakov

The nearly cloaking via transformation optics approach for the isotropic elastic wave fields is considered. This work extends the study of the nearly cloaking scheme to the elasticity system with residual stress in \mathbb{R}^{N} for N=2,3,…

Analysis of PDEs · Mathematics 2016-12-01 Yi-Hsuan Lin

This is a survey of approximate cloaking using transformation optics for acoustic and electromagnetic waves.

Analysis of PDEs · Mathematics 2019-02-01 Hoai-Minh Nguyen , Michael S. Vogelius