The aim of the $32m five-year Holographic Data Storage System project to exploit Stanford University’s holographic storage technology (CI No 2,804) is to have a write-once prototype in two years and a read-write one by 1999. Holographic storage has the potential to store 100Mb of data in a crystal the size of a sugar cube, and retrieve it 100 to 1,000 times faster than current techniques. In the new technology, lasers record images in the form of two-dimensional pages, and by varying the angles of the laser recording, multiple pages can be stacked and stored in the same three-dimensional space. The laser beams converge on a location within the cube, and store data by altering the patterns of the crystal’s electrons. Holographic technology simply senses the presence of light for a one, or the absence of light for a zero at the intersection of two laser beams. The advantage of holographic storage is that many patterns, such as a person’s name and picture, can be superimposed in the same image-recording medium. Holography enables several images to be layered over one another within a block of light-sensitive material, dramatically increasing the amount of data in a single space. Holographic data can also be retrieved much faster as the entire image is retrieved rather than one bit of computer code at a time, and has no moving parts. Stanford has already proven the technology for storing and reading, but data is still slow to write – about an hour to store 160Kb. Also participating are IBM Corp, GTE Corp, Eastman Kodak Co, Optitek Inc of Mountain View, Rochester Photonics Inc, Rockwell International Inc, SDL Inc of San Jose, and the universities of Arizona, Texas and Syracuse.
