Spatial Control of Liquid Crystal Pretilt Angle with UV Irradiation to Vertical Alignment Polyimide Film

Abstract

In recent years, liquid crystal (LC) optical elements such as LC lens and grating have shown remarkable development, owning to advances in photoalignment technologies. Various techniques have been reported to spatially control LC orientation in the azimuthal direction. However, there were few reports that LC orientation was spatially controlled in the polar direction. This study shows that LC pretilt angle is spatially controlled with ultra-violet (UV)-irradiation to the vertical alignment polyimide film, and the grating structure was fabricated using this alignment technique