Analysis of Liquid Crystal Response on Alignment Film Using Near-Field Scanning Optical Microscopy

Abstract

For the study of local dynamics of liquid crystal (LC) molecules at the alignment film interface, we developed a novel observation method based on near-field scanning optical microscopy (NSOM) with 3-dimensional resolving power. By employing a high-quality NSOM fiber probe, we could apply a uniform electric field to LC molecules and detect LC orientation change with high sensitivity and spatial resolution as high as 100 nm. To measure and regulate the distance between the probe end and the alignment film surface, we utilized the depth profile of evanescent field intensity penetrating from the interface as a feedback signal.