Application of holographic optical techniques to bulk memory

Current efforts to exploit the spatial redundancy and built-in imaging of holographic optical techniques to provide high information densities (>10⁶bit/cm²) without critical alignment and tight mechanical tolerances are reviewed. Read-write-erase in situ operation is possible but is presently impractical because of limitations in available recording media. As these are overcome, it should prove feasible to build holographic bulk memories with mechanically replaceable hologram plates featuring very fast (<2 μs) random access to large (>10⁸bit) data blocks and very high throughput (>500 Mbit/s). Using volume holographic storage it may eventually be possible to realize random-access mass memories which require no mechanical motion and yet provide very high (>10¹¹bit) capacity.