Electrically Controlled Birefringence of Thin Nematic Films

Abstract

This paper reports field‐induced realignment of a nematic liquid crystal. A thin nematic film, which has a negative dielectricanisotropy, is initially homeotropic. Application of a threshold field parallel to the optic axis distorts the nematic ordering and increases the film'sbirefringence in certain light‐propagation directions. Experimental results are given for threshold voltage, threshold width, optical contrast ratio, frequency response, angular field of view, electrical power consumption, and transient response. Light‐valve applications are described.