Features of backward waves and negative refraction in absorbing bi-isotropic media and metamaterials

Abstract

ABSTRACT Conditions of the excitation of backward electromagnetic waves and negative refraction in absorbing bi-isotropic layered media and metamaterials are investigated. Based on the exact analytical model, the features determined by absorption and inhomogeneity of the waves and possible metamaterial properties of the medium are ascertained. It is shown that only simultaneous realization of backward, backward with respect to the boundary between two media, and negative refraction is possible for each of the proper waves in a bi-isotropic layer. The conditions are obtained when two (one transmitted and one reflected waves) or all the four proper waves in the layer are backward and characterized by negative refraction on boundaries. Taking into account the calculation of Pointing’s vector and energy dissipation of the waves, it is shown that the well-known limitations on the chirality and nonreciprocity parameters require a clarification for the considered media.