Paper
17 June 2004 Experiment on two-dimensional data restoring in fault-tolerant holographic memory
Author Affiliations +
Abstract
We propose a fault-tolerant holographic memory (FTHM) composed of a pair of photorefractive crystals. This memory offers not only non-destructive readout but also data restoring function by only pure optical operations without any electrical controls. In writing process, the same holographic data are simultaneously recorded as index gratings to the crystals laid out in series. In reading process, a reading beam is diffracted by the index gratings in each crystal. Here, some of the diffraction beams are detected as an output beam, and the others are used as a feedback beam. The hologram in each crystal is continuously refreshed by the feedback beam from the other crystal since the feedback beam has the same information as the original holographic data. When the data refreshing effect by the feedback beams sufficiently exceeds the erasure effect by the exposure of the reading beam, the stored data are always maintained. Furthermore, even if a certain fault such as vibration and stray beam incidence happens, the lost data in one crystal are all-optically restored as long as the corresponding holographic data remain in the other crystal. The experiment with a two-dimensional image is carried out for the purpose of checking the data restoring function in FTHM. The two-dimensional image divided in quarters is recorded as into a pair of 45°-cut BaTiO3 crystals, and the original holographic data is successfully restored by the refreshing effect in the case that a quarter of the image in the one crystal is partially lost.
© (2004) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Terumasa Ito, Atsushi Okamoto, and Hisatoshi Funakoshi "Experiment on two-dimensional data restoring in fault-tolerant holographic memory", Proc. SPIE 5362, Advanced Optical and Quantum Memories and Computing, (17 June 2004); https://doi.org/10.1117/12.528748
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Crystals

Holograms

Laser crystals

Holography

Beam splitters

Diffraction

Multiplexing

Back to Top