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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

Using the framework of transformation optics, this paper presents a detailed analysis of a non-singular square cloak for acoustic, out-of-plane shear elastic, and electromagnetic waves. The generating map is examined in detail and linked to…

Mathematical Physics · Physics 2014-01-30 DJ Colquitt , IS Jones , NV Movchan , AB Movchan M Brun , RC McPhedran

In this work, we consider the problem of optimal design of an acoustic cloak under uncertainty and develop scalable approximation and optimization methods to solve this problem. The design variable is taken as an infinite-dimensional…

Optimization and Control · Mathematics 2021-03-17 Peng Chen , Michael R. Haberman , Omar Ghattas

The acoustic inverse obstacle scattering problem consists of determining the shape of a domain from measurements of the scattered far field due to some set of incident fields (probes). For a penetrable object with known sound speed, this…

Numerical Analysis · Mathematics 2023-02-15 Carlos Borges , Manas Rachh , Leslie Greengard

The concept of cloaking -- hiding objects from external detection -- has seen wide success in linear systems. Yet, translating these advancements to nonlinear mechanical systems remains an open challenge. Here, we present a new approach to…

An active interior cloak is composed of a conformal array of radiating sources surrounding a target object. With proper configuration, this array radiates a field discontinuity which cancels out any scattering which occurs when the object…

Applied Physics · Physics 2024-09-26 Paris Ang , George V. Eleftheriades

An approach to hiding objects levitating or flying above a conducting sheet is suggested in this letter. The proposed device makes use of isotropic negative-refractive-index materials without extreme material parameters, and creates an…

Optics · Physics 2010-09-29 Jingjing Zhang , Yu Luo , Niels Asger Mortensen

Invisibility or unhearability cloaks have been made possible by using metamaterials making light or sound flow around obstacle without the trace of reflections or shadows. Metamaterials are known for being flexible building units that can…

Concealing objects by making them invisible to an external electromagnetic probe is coined by the term cloaking. Cloaking devices, having numerous potential applications, are still face challenges in realization, especially in the visible…

It is known that design of elastic cloaks is much more challenging than the design idea for acoustic cloaks, cloaks of electromagnetic waves or scalar problems of anti-plane shear. In this paper, we address fully the fourth-order problem…

Classical Physics · Physics 2015-06-19 M. Brun , D. J. Colquitt , I. S. Jones , A. B. Movchan , N. V. Movchan

In an electromagnetic cloak based on a transformation approach, reduced sets of material properties are generally favored due to their easier implementation in reality, although a seemingly inevitable drawback of undesired reflection exists…

Transformation optics has shaped up a revolutionary electromagnetic design paradigm, enabling scientists to build astonishing devices such as invisibility cloaks. Unfortunately, the application of transformation techniques to other branches…

General Relativity and Quantum Cosmology · Physics 2015-06-11 C. García-Meca , S. Carloni , C. Barceló , G. Jannes , J. Sánchez-Dehesa , A. Martínez

Transformation optics constructions have allowed the design of cloaking devices that steer electromagnetic, acoustic and quantum waves around a region without penetrating it, so that this region is hidden from external observations. The…

Analysis of PDEs · Mathematics 2015-09-15 Matti Lassas , Ting Zhou

Transformation optics originating from the invariance of Maxwell's equations under the coordinate mapping has enabled the design and demonstration of many fascinating electromagnetic devices that were unconceivable or deemed impossible…

Materials Science · Physics 2013-11-25 Yungui Ma , Lu Lan , Wei Jiang , Fei Sun , Sailing He

Transformation optics constructions have allowed the design of cloaking devices that steer electromagnetic, acoustic and quantum waves around a region without penetrating it, so that this region is hidden from external observations. The…

Analysis of PDEs · Mathematics 2011-01-04 Matti Lassas , Ting Zhou

We derive the elastic properties of a cylindrical cloak for in-plane coupled shear and pressure waves. The cloak is characterized by a rank 4 elasticity tensor with 16 spatially varying entries which are deduced from a geometric transform.…

Materials Science · Physics 2009-11-13 Michele Brun , Sebastien Guenneau , Alexander B. Movchan

We propose to use morphing algorithms to deduce some approximate wave pictures of scattering by cylindrical invisibility cloaks of various shapes deduced from the exact computation (e.g. using a finite element method) of scattering by…

Computational Physics · Physics 2015-06-22 Ronald Aznavourian , Sébastien Guenneau

The scattering cancellation technique is a powerful tool to reduce the scattered field from electrically small objects in a specific frequency window. The technique relies on covering the object of interest with a shell that scatters light…

In this paper, we present the design of cylindrical and spherical electromagnetic cloaks working at visible frequencies. The cloak design is based on the employment of layered structures consisting of alternating plasmonic and non-plasmonic…

Optics · Physics 2008-08-01 Filiberto Bilotti , Simone Tricarico , Lucio Vegni

We develop and apply an optimization method to design invisibility cloaks. Our method is based on minimizing the forward scattering amplitude of the cloaked object, which by the optical theorem, is equivalent to the total cross section. The…

Optics · Physics 2021-03-09 Brian Slovick , Josh Hellhake