Topic
Transformation optics
About: Transformation optics is a research topic. Over the lifetime, 2687 publications have been published within this topic receiving 102378 citations.
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TL;DR: In this paper, an impedance-matched, low loss negative-index metamaterial superlens that is capable of resolving subwavelength features of a point source with a 0.13λ resolution was presented.
Abstract: Negative-index metamaterials are candidates for imaging objects with sizes smaller than a half-wavelength. The authors report an impedance-matched, low loss negative-index metamaterial superlens that is capable of resolving subwavelength features of a point source with a 0.13λ resolution, which is the highest resolution achieved by a negative-index metamaterial. By separating two point sources with a distance of λ∕8, they were able to detect two distinct peaks on the image plane. They also showed that the metamaterial based structure has a flat lens behavior.
199 citations
TL;DR: In this article, a theory of the homogenization of a certain class of metamaterials is stated, and a more widespread method of determining the material parameters of met amaterials based on the extraction of the refractive index and the characteristic impedance from the scattering matrix of the plate of the metammaterial is discussed.
Abstract: A theory of the homogenization of a certain class of metamaterials is stated. These metamaterials are volume lattices of electric and magnetic dipoles that are resonant with frequencies that are considerably lower than that of the first Bragg resonance of the lattice. It was shown that, for plates of a metamaterial, which are described by bulk material parameters, transition layers play an important role, and the known Drude notion of transition layers is significantly revised. The paper also discusses a more widespread method of determining the material parameters of metamaterials based on the extraction of the refractive index and the characteristic impedance from the scattering matrix of the plate of the metamaterial. The physical meaning of the material parameters obtained in this way is clarified, and the concept of Bloch lattices related to it is discussed. It is shown that the bulk material parameters and the parameters of transition layers can also be extracted from components of the scattering matrix of plates.
198 citations
TL;DR: An omnidirectional retroreflector is demonstrated, a device for faithfully reflecting images and for creating high visibility from all directions, that would normally require a dielectric singularity, an infinity in the refractive index in a real metamaterial.
Abstract: Transformation optics is a concept used in some metamaterials to guide light on a predetermined path. In this approach, the materials implement coordinate transformations on electromagnetic waves to create the illusion that the waves are propagating through a virtual space. Transforming space by appropriately designed materials makes devices possible that have been deemed impossible. In particular, transformation optics has led to the demonstration of invisibility cloaking for microwaves, surface plasmons and infrared light. Here, on the basis of transformation optics, we implement a microwave device that would normally require a dielectric singularity, an infinity in the refractive index. To fabricate such a device, we transmute a dielectric singularity in virtual space into a mere topological defect in a real metamaterial. In particular, we demonstrate an omnidirectional retroreflector, a device for faithfully reflecting images and for creating high visibility from all directions. Our method is robust, potentially broadband and could also be applied to visible light using similar techniques.
195 citations
TL;DR: The transformation-optics paradigm is extended to a complex spatial coordinate domain, in order to deal with electromagnetic metamaterials characterized by balanced loss and gain, giving special emphasis to parity-time (PT) symmetric metammaterials.
Abstract: We extend the transformation-optics paradigm to a complex spatial coordinate domain, in order to deal with electromagnetic metamaterials characterized by balanced loss and gain, giving special emphasis to parity-time ($\mathcal{P}\mathcal{T}$) symmetric metamaterials. We apply this general theory to complex-source-point radiation and anisotropic transmission resonances, illustrating the capability and potentials of our approach in terms of systematic design, analytical modeling, and physical insights into complex-coordinate wave objects and resonant states.
191 citations
Proceedings Article•
01 May 2011TL;DR: A novel type of nonlinearity in metamaterials is proposed, which is induced by mechanical deformation of the structure, and which relies on the counterplay between the electromagnetic attraction and the elastic repulsion to create a novel nonlinear response.
Abstract: We propose and demonstrate experimentally a novel type of nonlinearity in metamaterials, which is induced by mechanical deformation of the structure. The nonlinearity arises from the introduction of an extra degree of freedom in the metamaterial, which allows for elastic displacement of the strongly interacting structural elements (see Fig. 1a). This type of nonlinearity relies on the counterplay between the electromagnetic attraction and the elastic repulsion, and the induced deformation alters the electromagnetic response of the entire structure, leading to the novel nonlinear response of the metamaterial.
190 citations