Simulation of light propagation through birefringent substrates with periodical surface microrelief

The simulation of the light diffraction in optical anisotropic materials with the surface microrelief is proposed and improved on the base of approaches developed by Rokushima-Yamakita and Glytsis-Gaylord for layered anisotropic materials. A substrate is divided into a set of thin parallel binary gratings with quasihomogeneous properties along the normal to the layers and then matrices of light wave amplitude at layers' boundaries are calculated. This optical anisotropic gratings with surface microrelief approach is compared with direct integration of the Maxwell equations by the finite-difference time-domain method. The validity of both methods was checked for gratings with different periods reduced to wavelength as well as for a thin grating. The possibility of creating various optical components on the basis of this effect such as diffraction gratings, optical compensators, and various types of light scattering elements is considered.