Two-dimensional analysis of liquid crystal orientation at in-plane switching substrate surface using a near-field scanning optical microscope

The microscopic liquid crystal (LC) orientation distribution in an in-plane switching (IPS) LC display device has been studied using a near-field scanning optical microscope (NSOM). The new NSOM system, which features an improved metal-coated optical fiber probe and is specifically designed for LC orientation analysis, has enabled successful visualization of the two-dimensional LC orientation distribution at the substrate surface. The observed NSOM images can be reproduced by theoretical simulations. These images together with the simulations reveal that the uneven-level structure of the interdigitated electrodes causes the asymmetric local LC orientation distribution near the electrode edges.