Storing information in dual holographic images
US5039182A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 23, 1989 |
| Grant date | Aug 13, 1991 |
| Priority date | — |
| Expiry date | Oct 23, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S359/90
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A holographic storage system receives light having its linear polarization rotated from a reference linear polarization for carrying given information. The modulated light is stored as two distinct images in a photorefractive crystal, the images carrying the same information but being complementary projections of linear polarization rotations from the reference linear polarization in a given rotational sense. The images are stored in the same volume portion of the crystal. Upon readout, the two images are converted into modulated electrical signals. To reproduce the information, one of the modulated electrical signals is divided into the other modulated electrical signal. A function of square root of arc tangent is introduced into the signal processing at the output portion of the system.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.