Abstract 9404273 Shen This research focusses on liquid crystalline materials. Proposed investigations are in two general areas: studies of nonlinear optical effects in liquid crystals and use of novel optical techniques to study liquid crystals. The former includes laser-induced dc polarization, wave mixing, stimulated light scattering, laser-induced nonlinear dynamics, and so on. The latter emphasizes liquid crystalline properties that cannot be easily probed by other methods. Particular interest is on surface and interfacial properties of liquid crystals. They are of great importance to the advance of liquid crystal device technology, because it is often the surface alignment of liquid crystals that determines the bulk liquid crystal alignment needed for specific devices. These studies should also enhance our knowledge about liquid crystals and their responses to light which will help in our search for applications of liquid crystals as modern technological materials. %%% This research focusses on liquid crystalline materials. Liquid crystals are extraordinary optical materials. They have found many applications in display, memory, and sensor devices. Their optical properties are easily modified by external perturbations. An ordinary laser beam is often strong enough to effect the modification. Propagation of a laser beam in a liquid crystal can yield many unusual, but interesting, optical phenomena potentially useful for optoelectronics. Our research is to discover, examine, and understand these phenomena. The results will also allow us to devise new methods to probe various important properties of liquid crystals.