Patterned Photoalignment-Based One- and Two-Dimensional Liquid Crystal Forked Gratings

Based on the technology of patterned photoalignment of polymerizable nematic liquid crystal, one- and two-dimensional fork-dislocation gratings which enable formation of singular light beams (optical vortices) have been fabricated and examined. The proposed approach to the formation of a two-dimensional optical structure presents itself a combination of two one-dimensional gratings with mutually orthogonal orientations of the grooves. Phase structures of the formed singular beams as well as their spatial and polarization characteristics have been studied experimentally. The obtained results offer new potentialities in design of optical devices and systems for transformation of phase and polarization structures of light beams.