Evolution properties of polarization states of far-zone electromagnetic field scattered from an anisotropic medium.

Within the accuracy of the first-order Born approximation, expressions are derived for the cross-spectral density matrix of the electromagnetic field scattered from a three-dimensional (3D), spatially anisotropic medium. By using the analytical forms of the spectral degree of polarization (SDOP), semi-major axis, semi-minor axis, and orientation angle of the polarization ellipse, we illustrate the evolution properties of the polarization states of the far-zone scattered field. Dependences of the polarization ellipses on different combinations of correlation lengths of the medium and polarization of incident plane wave are also revealed through numerical simulations. It is shown that the polarization ellipse of the scattered field can be either stretched or squeezed along certain scattering angles, strongly depending on the anisotropic statistics of medium and polarization of incident plane wave. Our results substantially enrich the study on the reciprocal relations between the far-zone scattered properties and correlation statistics of a spatially anisotropic medium.