Electromagnetic plane wave diffraction by a cylindrical arc with edges: H-polarized case

An accurate hybrid method (numerical-analytical method) for the diffraction of H-polarized electromagnetic plane wave by perfectly electric conducting cylindrical bodies containing edges and a longitudinal slit aperture is proposed. This method is the combination of the Method of Moment and semi-inversion method. The current density function is expressed as the Chebyshev polynomials forming a complete orthogonal set of basis functions. Then, the initial problem is reduced to a system of linear algebraic equations. After inversion, the unknown coefficients are obtained. Then, near and far-field distributions, radar cross-sections are obtained. The resonances are observed for different values of the aperture size, radius of the arc, and the results are compared with previous outcomes.

Modified Theory of Physical Optics Approach to Diffraction by an Interface between PEMC and Absorbing Half-Planes

The scattering of electromagnetic plane waves by an interface, located between perfect electromagnetic conductor and absorbing half-planes is investigated. The perfect electromagnetic conductor half-plane is divided into perfect electric conductor and perfect magnetic conductor half-screens. The same decomposition is done for the absorbing surface. Then four separate geometries are defined according to this approach. The scattered fields by the four sub-problems are obtained with the aid of the modified theory of physical optics. The resultant scattering integrals are combined in a single expression by using key formulas, defined for the perfect electromagnetic conductor and absorbing surfaces. The scattering integral is asymptotically evaluated for large values of the wave-number and the diffracted and geometric optics fields are obtained. The behaviors of the derived field expressions are analyzed numerically.

The Diffraction by the Half-plane with the Fractional Boundary Condition

In this article, there is considered the electromagnetic plane wave diffraction by the half-plane with fractional boundary conditions. As a mathematical tool, the fractional calculus is used. The theoretical part is given based on which the near field, Poynting vector and energy density distribution are calculated. Interesting results are obtained for the fractional order between marginal values, which describes a new type of material with new properties. The results are analyzed.

Влияние пространственной дисперсии в металлах на оптические характеристики биметаллических плазмонных наночастиц

The problem of diffraction of an electromagnetic plane wave field on a core-shell nanoparticle composed of two plasmon metals is considered. The effect of spatial dispersion in metals on the absorption cross section is investigated on the basis of the Discrete Sources method. Various combinations of core and shell metals: Au@Ag and Ag@Au of spheroidal particles, as well as the effect of elongation and asymmetry of particle geometry on energy absorption are being studied. It was found that taking into account the spatial dispersion, both in the core and in the shell, leads to a significant decrease in the absorption cross section and a shift of the plasmon resonance to the shorter wavelength region.

Анализ поглощающих периодических структур, образованных цилиндрическими электромагнитными черными дырами

A 2D problem of electromagnetic plane wave scattering by 1D-periodic structures composed of cylindrical black holes arranged on a semi-infinite substrate is considered. Two algorithms corresponding to the cases of E- and H-polarization and based on the hybrid projection method accounting for the refractive index profiles in the black holes of a few types are developed. The algorithms are generalized also on the case of arrangement of the black holes on a PEC screen. A number of numerical results characterizing both the effectiveness of the algorithms themselves and performance of the absorbing structures with black holes are presented. Absorbing characteristics of the indicated structures are compared to the similar characteristic obtained for the structures of wedge elements.