ABSTRACT

The volume holographic data storage technology has advanced significantly in the past two to three decades owing to the improvement in holographic recording materials, lasers, liquid crystal spatial light modulators, beam steering techniques, CMOS cameras, and other optical components. One feature that makes volume holographic data storage extremely attractive is its natural ability for content addressable memory or associative retrieval. The applications of multiplexed volume holographic data storage in the areas of parallel optical image processing and three-dimensional displays will also have unique advantages. The major barrier for volume holographic data storage to become reality is the lack of a recording material with a much higher optical-sensitivity. Future research in new holographic recording materials will eventually bring this superior technology to our daily lives. Meanwhile, the development of multilayer optical disks, two-photon 3-dimensional bit optical storage, near field optical storage, spectral hole burning technology, five-dimensional storage, and microholographic multilayer optical disk, etc., will provide competitive optical approaches to high-density data storage. This entry briefly introduces various aspects of the volume holographic data storage technology, including the history, principle of operation, recording media, error correction, and associative retrieval applications. Major challenges as well as alternative high density optical data storage technologies are also briefly discussed. References are given for interested readers for further information.