Photoinduced Optical Anisotropy in Langmuir Blodgett Films as a New Method of Creating Bistable Anchoring Surfaces for Liquid Crystal Orientation

摘要

We report a new method to prepare surfaces that creates two degenerate states for liquid crystal orientation. The method uses Langmuir-Blodgett (LB) films exhibiting the effect of photoinduced optical anisotropy. We illuminate LB films twice with polarized light of perpendicular orientations to produce a special shape for the molecular distribution function in a LB film. Nematic liquid crystal molecules (NLC) aligned by these films can show two stable orientations, i.e. surface induced bistability. The results observed are interpreted in terms of a micro domain distribution in LB film. The origin of the bistability is “extrinsic”.