Design and Implementation of Near-Field Scanning Optical Microscope for Observation of Interfacial Liquid Crystal Orientation

A near-field scanning optical microscope (NSOM), optimized for observation of liquid crystal (LC) orientation at the LC/alignment layer interface, has been developed. The NSOM operates in the illumination mode using a metal-coated optical fiber probe together with a probe-positioning system based on the optical feedback technique. This novel system enables the depth profiling and two-dimensional imaging of the LC orientation distribution under an applied local electric field with high spatial resolution. In this paper we describe the design and implementation of the developed NSOM system and report its first application to the microscopic analysis of LC orientation at the LC/alignment layer interface.