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Transformation optics

About: Transformation optics is a research topic. Over the lifetime, 2687 publications have been published within this topic receiving 102378 citations.


Papers
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Journal ArticleDOI
TL;DR: In this article, a fully metallic Luneburg lens was proposed to produce a link between 3-D homogeneous surfaces and 2-D dielectric lenses where the propagation is only in the air.
Abstract: Non-Euclidean transformations have been recently proposed to produce a link between 3-D homogeneous surfaces and 2-D dielectric lenses. Therefore, the propagation in a geometrical surface has the same response of an equivalent refractive index distribution. By using this concept, we propose here a fully metallic Luneburg lens where the propagation is only in the air. Two metallic plates, following a curved shape, are employed to support the propagation mimicking the designed curvature. To reduce the height of the required curvature, the surface has been mirrored twice with respect to two $z$ constant planes. The lens is fed by 11 waveguide ports spaced with an angle of 12.5° providing 1-D beam scanning over an angular range of ±62.5°. A prototype is manufactured and measured with a good agreement with the simulated results between 25 and 36 GHz to demonstrate the concept.

128 citations

Patent
20 Apr 2012
TL;DR: In this paper, a metamaterial waveguide structure is disclosed, which includes a plurality of complementary metammaterial elements patterned on a conducting surface of the waveguide, and a Rotman lens is compressed by 27 percent along the optical axis while maintaining the beam steering range, gain and side lobe amplitudes over a broad frequency range.
Abstract: A metamaterial waveguide structure is disclosed. In some approaches the metamaterial waveguide structure is compressed along an optical axis using transformation optics techniques. An example is a Rotman lens that is compressed by 27 percent along the optical axis while maintaining the beam steering range, gain and side lobe amplitudes over a broad frequency range. In some approaches the metamaterial waveguide structure includes a plurality of complementary metamaterial elements patterned on a conducting surface of the waveguide.

128 citations

Journal ArticleDOI
TL;DR: In this article, the frequency-dependent elements of the effective permittivity and permeability tensors for arbitrary angles of incidence were retrieved for the fishnet metamaterial and it was shown that genuine effective material parameters can only be introduced if quite stringent constraints are imposed on the wavelength/unit cell size ratio.
Abstract: Although optical metamaterials that show artificial magnetism are mesoscopic systems, they are frequently described in terms of effective material parameters. But due to intrinsic nonlocal (or spatially dispersive) effects it may be anticipated that this approach is usually only a crude approximation and is physically meaningless. In order to study the limitations regarding the assignment of effective material parameters, we present a technique to retrieve the frequency-dependent elements of the effective permittivity and permeability tensors for arbitrary angles of incidence and apply the method exemplarily to the fishnet metamaterial. It turns out that for the fishnet metamaterial, genuine effective material parameters can only be introduced if quite stringent constraints are imposed on the wavelength/unit cell size ratio. Unfortunately they are only met far away from the resonances that induce a magnetic response required for many envisioned applications of such a fishnet metamaterial. Our work clearly indicates that the mesoscopic nature and the related spatial dispersion of contemporary optical metamaterials that show artificial magnetism prohibits the meaningful introduction of conventional effective material parameters.

127 citations

Journal ArticleDOI
TL;DR: In this paper, the optical properties of parity-time symmetric metamaterials composed of planar plasmonic waveguides were theoretically investigated, and it was shown how the initially isotropic material becomes both asymmetric and unidirectional.
Abstract: We theoretically investigate the optical properties of parity-time ($\mathcal{PT}$)-symmetric three-dimensional metamaterials composed of strongly coupled planar plasmonic waveguides. By tuning the loss-gain balance, we show how the initially isotropic material becomes both asymmetric and unidirectional. Investigation of the band structure near the material's exceptional point reveals several interesting optical properties, including double negative refraction, Bloch power oscillations, unidirectional invisibility, and reflection and transmission coefficients that are simultaneously equal to or greater than unity. The highly tunable optical dispersion of $\mathcal{PT}$-symmetric metamaterials provides a foundation for designing an unconventional class of three-dimensional bulk synthetic media, with applications ranging from lossless subdiffraction-limited optical lenses to nonreciprocal nanophotonic devices.

124 citations

Journal ArticleDOI
TL;DR: Using numerical simulation techniques, the transmission and reflection coefficients, or S parameters, for left-handed metamaterials are calculated in this article, using the newly developed commercially available code MICROWAVE STUDIO, which is based on the finite integration technique with the per...
Abstract: Using numerical simulation techniques, the transmission and reflection coefficients, or S parameters, for left-handed metamaterials are calculated. Metamaterials consist of a lattice of conducting, nonmagnetic elements that can be described by an effective magnetic permeability μeff and an effective electrical permittivity eeff, both of which can exhibit values not found in naturally occurring materials. Because the electromagnetic fields in conducting metamaterials can be localized to regions much smaller than the incident wavelength, it can be difficult to perform accurate numerical simulations. The metamaterials simulated here, for example, are based on arrays of split ring resonators (SRRs), which produce enhanced and highly localized electric fields within the gaps of the elements in response to applied time dependent fields. To obtain greater numerical accuracy we utilize the newly developed commercially available code MICROWAVE STUDIO, which is based on the finite integration technique with the per...

123 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202324
202269
202147
202070
2019100
201890