The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 02, 1993
Filed:
Mar. 05, 1991
Philip D Henshaw, Carlisle, MA (US);
Steven A Lis, Lexington, MA (US);
Sparta Systems, Inc., Lexington, MA (US);
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.