Process of making an achromatic hologram which is adapted to be reconstructed with white light

US4989929A · kind A · utility

Assignee

• Holtronic, GmbH · DE

Inventors

• Gunther Dausmann · Erding, DE
• Rudi T. de Jongh · Rosenheim, DE
• Klaus Gnadig · Munich, DE

Key dates

• Filing date: Nov 23, 1988
• Grant date: Feb 5, 1991
• Expiry date: Nov 23, 2008

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S359/90
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

A process is disclosed for making an achromatic hologram which is adapted to be reconstructed with white light and which is recorded on a photographic record carrier by means of an object beam and a reference beam of coherent monochromatic light in an operation in which the object beam and a reference beam of coherent monochromatic light in an operation in which the object beam passes through an image-forming optical element between the object and the recording material. The image forming element has a large relative aperture. When the first hologram has been recorded on the record carrier a reference beam is projected in a direction which is opposite to the direction of the reference beam used to record the first hologram and is thus used to reconstruct the object wave from the first hologram. The object wave from the first hologram is rearwardly projected through the optical element and used to form an image at the original position of the object and at that location is caused to interfere with a reference beam, whereby an undistorted image of the object is recorded as a second hologram on a second record carrier.