The transport of polarized radiation in anisotropic, spatially dispersive, weakly inhomogeneous and dissipative media with embedded sources is dealt with in terms of the (second-rank) radiation intensity tensor obtained on the basis of the geometrical optics far-field solution of the wave equation. Such an approach accounts for the effects of both wave energy absorption and emission from the medium, the former being related to the anti-Hermitian part of the dielectric tensor of the medium and the latter being expressed in terms of the autocorrelation of the source current density, which allows one to treat both polarized and unpolarized, as well as coherent and incoherent, sources. The polarization properties of the radiation, described on the basis of the polarization vectors of the two propagating electromagnetic eigenmodes, are investigated with respect to the effects of both the spatial inhomogeneity and birefringence of the medium, the latter, in particular, being connected with the relative change of phase of the two propagating modes over the relevant ray path. Each of the effects is discussed, and the connections with standard notions such as the specific intensity of the radiation and Stokes parameters are investigated, the state of thermodynamic equilibrium being considered as an example. The specific case of the polarization degeneracy in an isotropic medium is addressed in some detail. The case of a non-uniformly magnetized medium is also considered.
Dielectric properties of an inhomogeneous plasma