Nematic Liquid Crystals as Media for Real-Time Holography

Abstract

We report on a novel type of orientational photorefractive devices consisting of dye-doped or pure nematic liquid crystals. These systems can be employed as the recording media for real-time (dynamic) holography. Optical addressing of liquid crystal molecules is facilitated due to the natural tendency of molecular self-assembling in nematics and their easy reorientation upon action of an electric field. This field can be produced by incoming light via photoconductivity either in the bulk or at the surface of the nematic liquid crystal layer. We present an experimental study of dynamic self-diffraction of light on thin phase holograms formed in a nematic liquid crystal panel. Optically addressed spatial light modulators designed by us can be the active elements of image processing systems and in this communication we demonstrate the optical correlator performing image recognition.