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: It is shown that transformation optics can be applied to extend the functionalities of conventional optical devices and a Fourier lens is designed that can transform the image to its reciprocal space and operate for incident light of subwavelength profile.
Abstract: We show that transformation optics can be applied to extend the functionalities of conventional optical devices. In particular, geometrically compressing the input facet of any conventional optical elements can extend the input spatial frequency bandwidth. As an example, we design a Fourier lens that can transform the image to its reciprocal space and operate for incident light of subwavelength profile. An explicit design employing metal-dielectric layers is given for realization.
20 citations
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TL;DR: Based on quasi-conformal transformation optics, a 3D conformal lens made of isotropic and non-resonant metamaterial is designed, which can make a cylindrical conformal array behave similarly to a uniform linear array.
Abstract: In this paper, based on quasi-conformal transformation optics, a 3D conformal lens made of isotropic and non-resonant metamaterial is designed, which can make a cylindrical conformal array behave similarly to a uniform linear array. After discussion and simplification in the two-dimensional model, we realize the proposed lens by utilizing drilling-hole material in the three-dimensional structure. The ring-like shape and forward-only radiation make it possible to equip the lens on a cylindrical device.
20 citations
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TL;DR: A novel type of electromagnetic cloak designed to conceal an object in a corner is described, and its excellent performance is demonstrated by employing direct numerical simulation.
Abstract: We describe a novel type of electromagnetic cloak designed to conceal an object in a corner, and demonstrate its excellent performance by employing direct numerical simulation. Furthermore, we study the angular dependence and the effect of loss on the invisibility performance and compare ideal and simplified cloaks. The proposed structure has homogeneous constitutive parameters, which greatly simplifies practical realization.
20 citations
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TL;DR: In this paper, the existence of metamaterial blueprints describing, and fundamental limitations concerning, perfectly reflectionless omnidirectional electromagnetic absorbers (OEMAs) is demonstrated.
Abstract: We demonstrate the existence of metamaterial blueprints describing, and fundamental limitations concerning, perfectly reflectionless omnidirectional electromagnetic absorbers (PR-OEMAs). Previous attempts to define PR-OEMA blueprints have led to active (gain), rather than passive, media. We explain this fact and unveil new, distinct limitations of true PR-OEMA devices, including the appearance of an “electromagnetic horizon” on physical solutions. As practical alternatives we introduce alternative OEMA blueprints corresponding to media that, while not reflectionless, are nonetheless effective in absorbing incident waves in a manner robust to incident wave diversity.
20 citations
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TL;DR: This study extends the concept of electromagnetic cloaking of arbitrarily-shaped objects to a complex geometry by simulating the cloaking effect of toroidal invisibility cloaks using the generalized discrete-dipole approximation (DDA) method.
Abstract: The material properties of toroidal invisibility cloaks are derived based on the coordinate transformation method The permittivity and permeability tensors for toroidal cloaks are substantially different from those for spherical cloaks, but quite similar to those for 2D cylindrical cloaks because a singularity is involved at the inner boundary in both the cases The cloaking effect is confirmed by the electric field distribution in the vicinity of toroidal cloaks simulated from the generalized discrete-dipole approximation (DDA) method This study extends the concept of electromagnetic cloaking of arbitrarily-shaped objects to a complex geometry
20 citations