Optical information recording/reproducing apparatus, optical information recording/reproducing method
AssigneesArizona Board of Regents on Behalf of the University of Arizona, Hitachi, Ltd.
InventorsYuzuru Takashima, Kenichi SHIMADA
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Abstract
An optical information recording/reproducing apparatus and method thereof which compensate for the effect of mechanical instability on holographic data storage. A time dependent deviation profile of an optical beam during recording is determined. The time dependent deviation profile is related to a phase profile to be applied to a reference beam during recording or reproduction of a hologram, and the related phase profile is applied to the reference beam during recording or reproduction of the hologram.
Claims21
An optical information processing apparatus for recording information in a holographic medium, the apparatus comprising:
- a laser source which generates at least one optical beam including a reference beam and a signal beam;
- a beam control device which steers an incident angle of the reference beam with respect to the holographic medium to write data in the holographic medium based on interference of the reference beam and the signal beam in the holographic medium;
- a deviation profiler which obtains a time dependent deviation profile of the optical beam for one page of data recorded in the holographic medium at a nominally fixed angle of the incident angle of the reference beam;
- a processor programmed to relate the time dependent deviation profile to at least one of a phase profile and an amplitude profile to be applied to the reference beam;
- and
- an adaptive optical element which applies said at least one of the phase profile and the amplitude profile to the reference beam to compensate for time dependent deviations of the optical beam.
An optical information processing apparatus for reading information in a holographic medium, the apparatus comprising:
- a laser source which generates a reference beam;
- a beam control device which steers an incident angle of the reference beam with respect to the holographic medium to read data in the holographic medium;
- a processor programmed to relate a time dependent deviation profile, associated with an optical beam which recorded said data in the holographic medium, to at least one of a phase profile and an amplitude profile to be applied to the reference beam;
- an adaptive optical element which applies said at least one of the phase profile and the amplitude profile to the reference beam to compensate for time dependent deviations of the optical beam which occurred in the recording of said information;
- an optical reader which reads said data in the holographic medium.
A method of processing information in a holographic medium, comprising:
- determining a time dependent deviation profile of an optical beam which recorded or is recording one page of data in the holographic medium at a nominally fixed angle of the optical beam;
- and
- relating the deviation profile to at least one of a phase profile and an amplitude profile to be applied while processing said information in the holographic medium.
Dependencies are inferred from the claim text.