Liquid crystal light modulators with asymmetrical interfaces

摘要

Liquid crystal devices whose light transmission properties are respectively responsive to the polarity of an applied voltage enable the realization of high-speed modulators useful for communication and display purposes. Such a polar effect is achieved by establishing asymmetrical interfacial interactions between the surfaces of a liquid crystal layer and alignment layers disposed in respective contact with the surfaces. Asymmetry is introduced in the form of either different anchoring strengths or different tilt angles for liquid crystal molecules at the two surfaces. In either case, both quiescently and in response to an electric field applied perpendicular to the surfaces of the liquid crystal layer, the contour of the longitudinal axes of the molecules is thereby established to have different curvatures, each less than about 45 degrees, at the two surfaces.