Patent ID: 6043910
Filing Date: 2000-03-28
Classification: G02F,G03H

Abstract:
An active hologram for generating a plurality of modified wavefronts comprising:at least two layers of material capable of modulating radiation;means for applying a plurality of voltages to said layers; andmeans for illuminating said layers with radiation, wherein said layers include:at least one electro optic layer, having an index of refraction which changes with applied voltage so that the modulation imparted to illuminating radiation passing through any point on the hologram varies with applied voltage; andat least one substrate layer, having a surface profile defined by its thickness varying across the hologram so that the modulation imparted to illuminating radiation at a given applied voltage varies across the hologram, the profile of said substrate layer being arranged so as to define the wavefront generated at each of said plurality of applied voltages upon illumination.