Pseudo-Stokes parameter representation of light propagation in layered inhomogeneous uniaxial media in the geometric optics approximation

We study the propagation of normally incident, elliptically polarized light in layered inhomogeneous uniaxial structures by using the geometric optics approximation (GOA). We show that, in the GOA, light propagation can be described by the evolution of four real-valued pseudo-Stokes parameters. These parameters are linearly related to the familiar Stokes parameters and obey a simple first-order differential equation. Conservation of energy and angular momentum is preserved under this approximation.