Reflection and transmission matrices for plane anisotropic gradient structures with torsion

In this paper, we propose a $4 \times 4$ matrix method for calculating the components of the vectors of the electric and magnetic fields in an anisotropic gradient planar structure with rotation of the optical axis inside the layer, obtained using the semiclassical approximation: the Wentzel-Kramers-Brillouin (WKB) method. The resulting matrix notation of the solution, in contrast to the multilayer model, makes it possible to avoid artificial discontinuities in the optical properties of the medium and the field projections at the boundaries of the layers in the problem.