Radiation and low-frequency scattering of EM waves in a general anisotropic homogeneous medium

This paper focuses on a boundless homogeneous medium with general anisotropy of electromagnetic properties. The explicit exact form of the four spectral Green´s dyads Gˆ_νξ(k) is obtained and a coordinate-free representation of the four spatial Green´s functions Gˆ_νξ(x-x´) in terms of one scalar potential W(x-x´) is developed. On this basis, asymptotic expressions for the radiation field due to arbitrary sources are derived that show that the associated modes and the eigenmodes determine radiation along a singular optic axis and in all other directions, respectively. Using an integral equation approach and the theory of Newtonian potential, the problem of low-frequency scattering by a small anisotropic ellipsoidal body immersed into an anisotropic medium is solved analytically