Topological Optical Reorientation in Dye-Doped Nematic Liquid Crystals Induced by Light Beams

Light interaction with photosensitive liquid crystal (LC) materials is one of the most rapidly developing fields of soft-matter optics and photonics. One of these phenomena is a singular optical reorientation of anisotropic birefringent elastic media using a nonsingular Gaussian light beam beyond the paraxial approximation. The director field deformation is topologically nontrivial: it imprints the topology of a divergent beam. Adding dichroic dyes in a nematic LC significantly modifies the light-matter interaction processes. This is expected to significantly modify light-LC interaction, resulting in both new LC deformation and structuring light itself during propagation through the LC film. Light excitation of specific azobenzene compounds results in optical torque related to the anisotropic interaction between the dye and LC molecules. Light-induced elastic deformation leads to local variation of polarization and absorption. This project aims to investigate light-LC interaction in non-paraxial geometry.