Fast Cholesteric Liquid Crystal Light Switch Based on Field-Controlled Total Internal Reflection

Abstract
A new fast cholesteric liquid crystal light switch with response times in the microseconds region is presented. Light is partially transmitted or totally reflected depending upon the field-controlled position of the optic axis in a uniformly aligned short-pitch cholesteric subjected on an electric field perpendicular to the helix. Its performance is temperature independent in a broad temperature range and a contrast ratio of 20:1 is achieved.