Photoinduced alignment of nematic liquid crystal on the polymer surface microrelief

A polymer film surface modified by laser illumination was used as a command surface for nematic liquid crystal (LC). Azobenzene-containing polyurethanes were taken for the material of the film. A relief grating inscribed by laser illumination onto the surface of these polymers induced a reorientation of the LC director from the initial homeotropic alignment. Possible applications of the described processes include command-surface creation for liquid-crystal displays, reversible and adaptable liquid-crystal structures for laser-beam targeting and aiming, etc.