Patent ID: 6280884
Filing Date: 2001-08-28
Classification: G02F,G03H,G11B

Abstract:
A process for holographic storage in a photorefractive polymeric optical article comprising a polymer and a non linear optical chromophore comprising the steps of (i) exposing the article to electromagnetic radiation having an intensity of at least 0.05 W/cm.sup.2 to obtain an absorbed energy/unit volume of at least 1.times.10.sup.4 J/cm.sup.3 from said radiation to activate the article without forming an index grating and (ii) exposing said article to an external electric field and electromagnetic radiation to cause formation of an index grating provided one of the step (i) or step (ii) exposures is with two intersecting beams of coherent electromagnetic radiation and the other step exposure is a flood exposure.