Patent ID: 6882613
Filing Date: 2005-04-19
Classification: G03H,G11B

Abstract:
1. A method of storing data in the form of holograms in a crystal, comprising; providing a cylindrical crystal formed about an axis, the crystal having an axially facing surface and a peripheral surface extending transverse to the axially facing surface; from a source of laser light, providing a signal beam containing the data and focusing the signal beam through the axially facing surface of the cylindrical crystal; from a source of laser light, providing reference beam and focusing the reference beam through the peripheral surface of the cylindrical crystal to interfere with the signal beam and thereby write a hologram in the cylindrical crystal; rotating the cylindrical crystal and laser light with respect to one another about the axis of the cylindrical crystal to write additional holograms in the cylindrical crystal in an annular array; indexing the crystal axially with respect to the beams to write numerous annular arrays stacked axially within the crystal; reading the hologram out of the crystal by passing a reference beam therethrough to diffract from the holograms and produce a diffracted beam including the data of the holograms; converting the transmitted reference beam to a phase conjugate beam that diffracts from the hologram, and reading the phase conjugate beam with a detector.