In this paper we theoretically study (with plane wave expansion and finite-difference time-domain models) waveguiding effect of the 2D hexagonal dielectric photonic crystal tiling. The structure is made of GaAs dielectric rods in air. We perform the calculations of the band structures, equi-frequency contours and electromagnetic propagation through the new type of the photonic crystal and self-collimation waveguides making it possible for application.
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We present a theoretical research of the optical properties of the (3,12,12) hexagonal 2D Archimedean photonic crystals. The structures are made of GaAs dielectric rods in air. Our research is mainly focused on analyzing symmetry properties of the modes and the appearance of the uncoupled modes which strongly affects the propagation of the wave and the optical performances of the material.
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We apply transformation optics to structures in which the electromagnetic field is confined by highly conducting coatings. The possibility of changing the field propagation direction without perturbation is demonstrated on the example of a waveguide bend. Using this approach it is also possible to reshape a confined structure in order to meet certain external requirements and to redistribute a field in order to obtain desired field distribution. The structure implementation implies replacing a part of given confined structure with a metamaterial designed using the technique of transformation optics. Simplification of structure realization based on using reduced set of material parameters is examined. Our theoretical considerations are confirmed by full wave finite element simulations of a waveguide bend.
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Cloaking devices designed using the coordinate transform approach were shown to be realizable, at least in principle, within the realm of electromagnetic metamaterials. In this paper we investigate the strictness of conditions imposed on the parameters of metamaterial cloaks by calculating the degree of wave scattering when those parameters have variations with respect to theoretically ideal values. A simple idea is used to obtain analytic results for the case of the nonideal two-dimensional cloaking cylinder. Also, results of realistic finite element simulations of the Helmholtz equation are presented and it is found that they are in excellent agreement with the analytic results.
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We consider metamaterial slabs composed of perfectly conducting split-ring resonators. Assuming bianisotropic constitutive relations, we describe an S-parameter retrieval method that allows us to obtain the full material parameter tensors from numerically calculated S parameters. The retrieval has been done for various angles of incidence, ranging from 0° to 75°. It has been found that the parameters depend on the angle of incidence, but that this dependence is relatively small.
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