Patent ID: 6730442
Filing Date: 2004-05-04
Classification: G02F,G03H

Abstract:
A method for contact recording at least one hologram comprising:arranging at least a first master hologram having an electrically controllable, continuously variable diffraction efficiency including at least diffraction efficiency states ON and OFF and at least a first holographic blank in optical contact and a second master hologram with electrically controllable variable diffraction efficiency and a second holographic blank in optical contact to form a master/blank assembly; exposing the master/blank assembly to a pre-recording beam; and exposing the master/blank assembly to a recording beam, the continuously variable first master hologram is switched OFF during exposure of the master/blank assembly to the pre-recording beam and the first master hologram is switched ON during exposure of the master/blank assembly to the recording beam, thereby forming a first replica of the first master hologram in the first holographic blank; wherein the master/blank assembly remains optically contacted throughout each exposure thereby forming the first replica of the at least a first master hologram in the at least a first holographic blank, wherein the first replica exhibits the electrically controllable, continuously variable diffraction efficiency of the at least a first master hologram and includes diffraction efficiency states ON and OFF; and further wherein the first master hologram and the first replica are switched OFF during each of the following, exposure of the second holographic blank to a pre-recording beam, recording of the second master hologram with electrically controllable variable diffraction efficiency in the second holographic blank, and exposure of a resulting second replica to a post-recording beam.