Accession Number : ADD014894

Title :   Erasable Optical Memory Material from a Ferroelectric Polymer.

Descriptive Note : Patent, Filed 12 Sep 85, patented 15 Mar 88,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Ogden, T R ; Gookin, Debra M

Report Date : 15 Mar 1988

Pagination or Media Count : 10

Abstract : Conventional magnetic storage technology is well advanced and a wide variety of magnetic tapes and disks have evolved. Most are erasable and have very long storage lifetimes. The present invention is directed to providing an apparatus for optically storing, erasing and rewriting digital information and having long term chemical and physical stability. A thin polyvinylidene-fluoride copolymer film having its Curie temperature below its melting point has a potential connected across it. The electric field impressed across the film is less than its coercive field. A laser writing beam heats a spot so that the coercive field is less than the applied electric field to pole the material at that spot. When the writing beam is removed, the polarization of the spot is stored. A polarized reading beam of less intensity than the writing beam is rotated in accordance with the polarization of the spot and information is retrieved. Optionally, the applied field is removed during reading. Erasure is accomplished by heating the recorded spots have the Curie temperature in the absence of an applied field.

Descriptors :   CHEMICALS, COERCIVE FORCE, CURIE TEMPERATURE, DIGITAL SYSTEMS, DISKS, ELECTRIC FIELDS, ERASURE, FERROELECTRIC MATERIALS, LASER BEAMS, LONG LIFE, LONG RANGE(TIME), MAGNETIC MATERIALS, MAGNETIC TAPE, MELTING POINT, MEMORY DEVICES, OPTICAL MATERIALS, OPTICAL STORAGE, PHYSICAL PROPERTIES, POLARIZATION, POLYMERS, READING, STABILITY, STORAGE, WRITING

Subject Categories : Computer Hardware

Distribution Statement : APPROVED FOR PUBLIC RELEASE