Inclined Homeotropic Alignment Control of Liquid Crystals on Photo-Cross-Linked Polymer Film by Slantwise Nonpolarized Ultraviolet Light Irradiation

The photoalignment of liquid crystals (LC) on a photo-cross-linkable polymer film was realized by the use of slantwise nonpolarized ultraviolet (NP-UV) light irradiation. The LC aligned homeotropically with an inclination, and the inclined direction was opposite to that of the incident NP-UV light propagation. By changing the irradiation angle and time, the inclination of the LC could be controlled. The alignment mechanism of the LC can be explained by the interaction between the LC and the photo-cross-linked group of the polymer film.