Optical memory method and apparatus utilizing frequency channeling and Stark effect
US5191574A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 5, 1991 |
| Grant date | Mar 2, 1993 |
| Priority date | — |
| Expiry date | Mar 5, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/0065
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Apparatus for storage and retrieval of digital data includes a multidimensional holographic storage medium for storing phase holographic images representative of the digital data. Selected regions of the medium are independently addressable by a beam of light. The storage medium is a spectral hole burning material having absorption regions independently addressable by selected frequencies of light, and includes selectively bleached absorption structures forming frequency channels. An external electric field of selected voltage can be applied to the storage medium to induce Stark effect broadening of the spectral holes, so that at a given frequency of light, a different phase hologram can be stored for each of a plurality of voltages, whereby multiple phase holograms can be stored for each frequency of light. Alternatively, physical stress can be applied to the storage medium to induce a stress field and associated broadening.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.