Balakhonova N. Anomalous phenomena caused by excitation of surface plasmon polaritons in the optical range on diffraction gratings

Subject under investigation: resonant effects caused by excitation of surface plasmon polaritons of visible and infra-red ranges on the metallic diffraction gratings formed by periodic corrugation of the surface or by the periodic modulation of the complex refractive index. Purpose: the theoretical description of phenomena which occur for resonance diffraction on the one-dimensional metallic gratings, namely total suppression of the specular reflection and the effects, which can accompany it (increase of amplitude of a field of one polariton and decreasing up to zero of amplitude of a field another, reflection of light in the autocollimating mode), polarization conversion, conversion arbitrary of polarized wave in linearly polarized in a given direction. Methods: resonance perturbation theory, theory of complex variables, numerical calculations on the PC in the program "Mathcad". Results, innovation: There are examined cases with excitation of a single or simultaneously both surface plasmon-polaritonson the metallic diffraction gratings, the multiple resonance case. The dependence of the diffracted wave amplitudes on the parameters of the problem (angle of incidence, wavelength and the parameters of the grating) is obtained for an arbitrary light wavelength and such grating materials for which the modulus of the imaginary part of the surface impedance is much greater than its real part. The conditions of realization of various resonant effects such as the polarization conversion, the total suppression of the specular reflection (TSSR), the total suppression of one of the waves or even of all homogeneous diffracted waves and others are obtained. Specifically, the case of TSSR of an arbitrary polarized incident wave is predicted. Three specific classes of gratings for which TSSR occurs in one or two points and along a part of some li--ne in the plane "angle of incidence - wavelength" are indicated.