HOLOGRAPHIC ARTICLE AND PROCESS FOR MAKING SAME

摘要

A holographic article preferably including a plurality of superimposed and/or spatially adjacent linear gratings, each of which has a spatial frequency different from that of the other gratings. The articles are formed as a result of an interference fringe field produced by two mutually coherent light beams impinging onto an assembly of a two-dimensional transparency and a photosensitive medium.