Browsing by Author "Sukharevsky, Ilya O."
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Item Open AccessManipulation of backscattering from a dielectric cylinder of triangular cross-section using the interplay of go-like ray effects and resonances(Institute of Electrical and Electronics Engineers, 2015) Sukharevsky, Ilya O.; Nosich, A. I.; Altıtaş, Ayhan; Sukharevsky, Ilya O.; Altıtaş, AyhanA triangular dielectric cylinder (dielectric prism) of the size, in cross-section, comparable to or moderately larger than the wavelength is a scatterer, which blends together two different types of electromagnetic behavior: geometrical optics (GO) and resonance. As shown in this paper, the first is responsible, for instance, for enhanced reflection from an isosceles 90° prism, if illuminated from the base. The second is responsible for the peaks in the total scattering and absorption cross-sections (ACSs) at the natural-mode frequencies. The numerical analysis is performed by solving the well-conditioned Muller-type boundary integral equation (IE) discretized using an algorithm with controlled accuracy. Item Open AccessTest of accuracy of the generalized boundary conditions in the scattering by thin dielectric strips(IEEE, 2014-05) Nosich, A. I.; Shapoval, O. V.; Sukharevsky, Ilya O.; Altıntaş, AyhanThe two-dimensional (2D) scattering of the E and H-polarized plane electromagnetic waves by a free-standing thinner than the wavelength dielectric strip is considered numerically. Two methods are compared: singular integral equations (SIE) on the strip median line obtained from the generalized boundary conditions for a thin dielectric layer and Muller boundary integral equations (BIE) for arbitrarily thick strip. The comparison shows the domain of acceptable accuracy of approximate model derived for thin dielectric strips. © 2014 IEEE. Item Open AccessValidation of higher-order approximations and boundary conditions for lossy conducting bodies(Institute of Electrical and Electronics Engineers, 2014-09) Sukharevsky, Ilya O.; Altıntaş, Ayhan; Sukharevsky, Ilya O.; Altıntaş, AyhanThe problem of high-frequency diffraction by a smooth lossy body with high conductivity is considered. In addition to the geometrical optics approximation, additional asymptotic terms are derived to take into account the curvature of the boundary and material properties. Since these higher-order terms are derived by taking into account exact boundary conditions, it is easy to learn about the limitations of impedance conditions and to determine more accurate approximate conditions. The obtained higher-order boundary conditions and their limitations are numerically validated by solving Muller's second-kind integral equations. © 2014 IEEE. Item Open AccessValidity and limitations of the median-line integral equation technique in the scattering by material strips of sub-wavellength thickness(Institute of Electrical and Electronics Engineers, 2014-07) Sukharevsky, Ilya O.; Shapoval, O. V.; Altıntaş, Ayhan; Nosich, A. I.; Sukharevsky, Ilya O.; Shapoval, O. V.Considered is the 2-D scattering of a plane wave by a thin flat material strip. The data obtained by using the empirical method of generalized boundary conditions and singular integral equations on the strip median line are compared with the results of solving the Muller boundary integral equation that takes full account of strip thickness. Discretization of integral equations in both cases is performed using the Nystrom methods that lead to convergent algorithms. Numerical results cover E and H polarizations and two types of thin strips: conventional dielectric and metal in the optical range. The validity and limitations of approximate model are established and discussed. Item Open AccessValidity of generalized boundary conditions and singular integral equation method in the scattering of light by thin dielectric strips(IEEE, 2014) Shapoval O. V.; Sukharevsky, Ilya O.; Altıntaş, AyhanWe consider the two-dimensional (2D) scattering of a plane wave of light by a thin flat dielectric nanostrip. Empirical method of generalized boundary conditions and singular integral equations on the strip median line is compared with Muller boundary integral equations method that does not assume the strip thickness to be small. The conclusions are achieved about the validity of approximate models for thin dielectric strips.