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Here we present the results of full experimental characterization of broadband cloaking of a finite-sized metallic cylinder at X-band. The cloaking effect is characterized by measuring the bistatic scattering patterns of uncloaked and…

We report the experimental verification of metamaterial cloaking for a 3D object in free space. We apply the plasmonic cloaking technique, based on scattering cancellation, to suppress microwave scattering from a finite-length dielectric…

Materials Science · Physics 2018-05-21 David Rainwater , Aaron Kerkhoff , Kevin Melin , Jason Soric , Gabriel Moreno , Andrea Alu

A new type of cloak is discussed: one that gives all cloaked objects the appearance of a flat conducting sheet. It has the advantage that none of the parameters of the cloak is singular and can in fact be made isotropic. It makes broadband…

Optics · Physics 2009-11-13 Jensen Li , J. B. Pendry

We demonstrate that metamaterial devices requiring anisotropic dielectric permittivity and magnetic permeability may be emulated by specially designed tapered waveguides. This approach leads to low-loss, broadband performance. Based on this…

Trajectory of surface gravity waves in potential flow regime is affected by the gravitational acceleration, water density, and seabed depth. While the gravitational acceleration and water density are approximately constant, the effect of…

Fluid Dynamics · Physics 2022-04-11 Takahito Iida , Ahmad Zareei , Mohammad-Reza Alam

Fundamental bounds on the performance of monochromatic scattering-cancellation and field-zeroing cloaks made of prescribed linear passive materials occupying a predefined design region are formulated by projecting field quantities onto a…

Optics · Physics 2021-07-06 Lukas Jelinek , Mats Gustafsson , Miloslav Capek , Kurt Schab

In recent years a remarkable progress was made in the construction of spatial cloaks using the methods of transformation optics and metamaterials. The temporal cloaking, i.e. the cloaking of an event in spacetime, was also widely studied by…

Mathematical Physics · Physics 2019-02-12 Gregory Eskin

We model a particle entering a complicated system from free space using an infinite chain of simple harmonic oscillators coupled to a finite, $n$-site cluster. For a particle wavepacket with small wavenumber, an expression for the time…

Quantum Physics · Physics 2018-12-13 Erin Crawley

Cloaking using a volumetric structure composed of stacked two-dimensional transmission-line networks is verified with measurements. The measurements are done in a waveguide, in which an array of metallic cylinders is inserted causing a…

We consider transformation-optics based cloaking in acoustic and electromagnetic scattering. The blueprints for an ideal cloak use singular acoustic and electromagnetic materials, posing server difficulties to both theoretical analysis and…

Analysis of PDEs · Mathematics 2014-09-03 Hongyu Liu , Gunther Uhlmann

Primordially formed extended dark objects would accrete baryonic matter and impact the ionisation history of the Universe. Insisting on consistency with the anisotropies of the cosmic microwave background, we derive constraints on the dark…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-01 Djuna Croon , Sergio Sevillano Muñoz

We can think of a lensed quasar as taking the Hubble time, shrinking it by \~10^{-11}, and then presenting the result to us as a time delay; the shrinking factor is of the order of fractional sky-area that the lens occupies. This cute fact…

Astrophysics · Physics 2009-11-10 Prasenjit Saha

All the thermal cloaks reported in the literature can be used to thermally hide an object inside the cloak. However, a common limitation of this kind of thermal cloaks is that the cloaked object cannot feel the external heat flow since it…

Materials Science · Physics 2013-12-12 Y. Gao , J. P. Huang

The ability to render objects invisible using a cloak - not detectable by an external observer - for concealing objects has been a tantalizing goal1-6. Here, we demonstrate a cloak operating in the near infrared at a wavelength of 1550 nm.…

Optics · Physics 2009-09-30 Lucas H. Gabrielli , Jaime Cardenas , Carl B. Poitras , Michal Lipson

We consider a novel method of cloaking objects from the surrounding electromagnetic fields in the microwave region. The method is based on transmission-line networks that simulate the wave propagation in the medium surrounding the cloaked…

Classical Physics · Physics 2009-11-13 Pekka Alitalo , Olli Luukkonen , Liisi Jylhä , Jukka Venermo , Sergei Tretyakov

The experimental realization of cloaks for electromagnetic fields has been possible only in reduced schemes because of extreme material conditions required in exact cloaks. Here we analytically demonstrate that a simple arrangement of two…

Superconductivity · Physics 2011-12-14 Carles Navau , Jordi Prat-Camps , Alvaro Sanchez

Single-shot diffractive imaging of truly 3D structures suffers from a dimensional deficiency and does not scale. The applicability of "ankylography" is limited to objects that are small-sized in at least one dimension or that are…

Optics · Physics 2015-05-18 Haiqing Wei

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…

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…

We design a device that generates fields canceling out a known probing field inside a region to be cloaked while generating very small fields far away from the device. The fields we consider satisfy the Laplace equation, but the approach…

Mathematical Physics · Physics 2015-06-03 Fernando Guevara Vasquez , Graeme W. Milton , Daniel Onofrei