Patent ID: 6456419
Filing Date: 2002-09-24
Classification: G02B,G02F

Abstract:
An electro-optical spatial light modulator, for imposing a spatial phase-modulation on a coherent light beam, comprising:a set of drive electrodes, distributed in an array, with each electrode arranged to receive a respective oscillating electrical excitation; a liquid crystal material, arranged to receive the coherent light beam and disposed in proximity to said set of drive electrodes so as to receive electrical excitations in local regions from said drive electrodes, said liquid crystal material having a dielectric coefficient which varies in said local regions in relation to the frequency of the local electrical excitation received by said regions; and a transparent top electrode, disposed on a first surface of said liquid crystal material and arranged to receive and transmit the coherent beam; wherein said drive electrodes comprise flat, reflective electrodes distributed in a pattern across a second surface, separated from said first surface by said liquid crystal material so that said first and second surfaces define a layer of liquid crystal material; and wherein said excitations are oscillating electrical potentials applied between said transparent top electrode and said drive electrodes, thereby establishing oscillating electrical fields in said liquid crystal layer.