Method and apparatus for positioning a light beam on a holographic media
US5621549A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 21, 1995 |
| Grant date | Apr 15, 1997 |
| Priority date | — |
| Expiry date | Aug 21, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/08564
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An apparatus for positioning a data and reference beam onto the surface of a holographic storage media (10) includes a laser (16) for generating the reference beam, and a first reflecting surface (18) for positioning the output of the laser (16) along the y-axis. The beam is split into a data beam and a reference beam by a beam splitter (24) with the data beam directed toward an SLM (36) and the reference beam (26) directed toward an angle multiplexing reflective surface (40). The data beam during a record operation is reflected from the surface of the SLM (36) to a transform lens (34) and then to a column (35) on the surface of a holographic storage media (10). The reference beam is reflected from a reflective surface (40) at a predetermined angle determined by the position of the reflective surface (40) to an HOE (46) for redirection to the surface of the storage media (10) to interfere with the data beam. During a data reconstruction operation, only the reference beam is generated. This results in a reconstructed image being directed toward an imaging lens (52) and then to a detector (54).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.