We review the crucial properties of a phase-encoded volume holographic storage system in terms of data quality and security, which are the key issues of any bulk memory system. Two major problems which need to be tackled in holographic storage systems in terms of data quality are the hologram erasure during readout and the data encoding schemes for error-free reconstruction.
We present a novel storage material, (bismuth tellurite crystals - Bi2TeO5), which has the potential to overcome the volatility problem and avoiding the need of any further fixing. Regarding data encoding schemes, we present a general approach of gray scale modulation coding in order to improve the data capacity in comparison to normal modulation coding, while the bit error rate maintains low.
Data security in a phase encoded system can be realized by exploiting its special multiplexing characteristics. We present different encryption techniques and investigate their decryption probability.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.