Compact-sized and broadband carpet cloak and free-space cloak.
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TLDR
The first experimental demonstration of broadband and low-loss directive free-space cloak and compact-sized carpet cloak realized using non-resonant metamaterials in the microwave frequency represents a major step towards the real applications of invisibility cloaks.Abstract:
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: free-space cloaks, which can render objects in free space invisible to incident radiation, and carpet cloaks (or ground-plane cloaks), which can hide objects under the conducting ground. The first free-space and carpet cloaks were realized in the microwave frequencies using metamaterials. The free-space cloak was composed of resonant metamaterials, and hence had restriction of narrow bandwidth and high loss; the carpet cloak was made of non-resonant metamaterials, which have broad bandwidth and low loss. However, the carpet cloak has a severe restriction of large size compared to the cloaked object. The above restrictions become the bottlenecks to the real applications of free-space and carpet cloaks. Here we report the first experimental demonstration of broadband and low-loss directive free-space cloak and compact-sized carpet cloak based on a recent theoretical study. Both cloaks are realized using non-resonant metamaterials in the microwave frequency, and good invisibility properties have been observed in experiments. This approach represents a major step towards the real applications of invisibility cloaks.read more
Citations
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Proceedings ArticleDOI
Experimental verification of carpet cloak realized with dielectric cylinders
TL;DR: Based on coordinate transformation, a carpet cloak made from nonmagnectic dielectric cylinders is designed, simulated and tested experimentally in this article, where the periodicity of the cylinders is manipulated to achieve the required dielectrics map and therefor the propagate direction of the electromagnetic waves.
Journal ArticleDOI
Homogeneous near-perfect invisible ground and free space cloak
TL;DR: A general approach to design near perfect invisible ground and free space cloaks is introduced in this article, which leads to homogeneous constitutive parameters for the cloaks without any singularities.
Proceedings ArticleDOI
Ultrathin carpet cloak based on ring resonators
TL;DR: In this article, an ultrathin carpet cloak based on a metasurface with ring resonators is proposed to suppress the scattering from a triangular bump of a Gaussian beam by manipulating the reflection phase along the edge of the bump.
Journal ArticleDOI
Broadband negative refractive index at visible range with composite materials
TL;DR: In this article, composite media based on metamaterials including random distribution of spherical nanoparticles in a polymeric foam host are suggested to achieve negative effective refractive index in the visible spectrum.
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TL;DR: This work describes here the first practical realization of a cloak of invisibility, constructed with the use of artificially structured metamaterials, designed for operation over a band of microwave frequencies.
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Hiding under the Carpet: A New Strategy for Cloaking
TL;DR: A new type of cloak is discussed: one that gives all cloaked objects the appearance of a flat conducting sheet that has the advantage that none of the parameters of the cloak is singular and can in fact be made isotropic.