Surface electromagnetic waves at an anisotropically conducting artificial interface

Surface electromagnetic waves propagating along an anisotropically conducting interface of two different dielectrics have been theoretically investigated. The flat surface of the interface contains a one-dimensional array of thin metal wires. It was assumed that both the lattice constant of the array and the diameter of the wires are far less than the lengths of the surface waves. It has been shown that the surface electromagnetic waves may propagate along the interface at frequencies which are far lower than the plasma frequency of a metal, and the electric field of the waves is always perpendicular to the wires in any propagation directions. The existence conditions, dispersion relations, and energy fluxes of the surface waves have been derived. It has been demonstrated that the surface electromagnetic waves can be excited by means of the transition radiation and beam instability effects.