Patent ID: 6166833
Filing Date: 2000-12-26
Classification: G03H

Abstract:
A method for making a hologram filter in a transparent material, for reconstructing an image by passing coherent light of a single frequency through the hologram filter, the light having a certain wavelength in the transparent material, comprising the steps of:(a) computing a transform of the image, said transform having, at each of a plurality of discrete points in a transform space, a transform amplitude A and a transform phase .phi.;(b) partitioning the material into a plurality of contiguous pixels of substantially equal dimensions, each said pixel corresponding uniquely to one of the points; and(c) for each point:(i) determining a set of encoding parameters that correspond to A and .phi., said set including at least two encoding phases; and(ii) for each of said at least two encoding phases: forming an optical path length difference, through a part of said corresponding pixel in the material, relative to a reference optical path length, substantially equal to the wavelength of the light in the transparent material multiplied by said each encoding phase modulo 2.pi..