Optical data storage by selective localized alteration of a format hologram
US6212148A · kind A · utility
20Cited by
30References
31Claims
0Family size
Assignee
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Key dates
| Filing date | Jan 30, 1998 |
| Grant date | Apr 3, 2001 |
| Priority date | — |
| Expiry date | Jan 30, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H2260/12
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Digital data bits are stored at storage locations at plural depths within a holographic storage medium as selective, localized alterations in a format hologram. Micro-localized regions of a reflection format hologram extending throughout the medium are deleted by focusing a high-power laser beam at desired storage locations. The deletion regions have a lower reflectivity than the surrounding parts of the format hologram. Tunable-focus storage and retrieval heads, as well as dynamic aberration compensators, are used for multi-depth access. Storage and retrieval may each be achieved with a single head.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.