Liquid Crystal Alignment by Holographic Surface Relief Grating Inscribed on Azo-Polymer Film

摘要

We found that the surface relief grating (SRG) made the nemntic liquid crystal (LC) align along the grating direction. The SRGs ware photo-fabricated cm a liquid crystalline azobenzane side-chain polymer film by the conventional holographic method. The twisted nemntic liquid crystal- (TNLC) cell was prepared using two SRG substrates or two rubbed- polyimide substrates as alignment layers, and the LC alignment was investigated by measuring the transmittance of a 90 deg -TNLC cell located between crossed polarizers. The LC aligning process was studied in-situ using the hybrid LC cell with the rubbed polyimide substrate and the SRG substrata as the reference and the test alignment layers, respectively. The in-situ transmission data- show that the topological effect by the SRG formation and the intermolecular interaction effect by the azo chromophore alignment compete with each other