Advances in devices such as digital video discs or DVDs and digital cameras bring the promise of storing massive amounts of information with holograms closer to reality, a speaker said Sunday at the Data Storage Conference and Exhibition. A commercial prototype for a holographic drive should be available next year, said Lisa Dhar, vice president of media development and founder of InPhase Technologies, a Longmont, Colo.-based company focused on bringing holographic storage to market.
The device could include a compact disc-sized removable disc holding 100 gigabytes of data, she said, and eventually could store tens of terabytes. The former is enough capacity for several days' worth of full-motion video, while the latter would comfortably hold several years' worth of records for a small corporation. Dhar's presentation included video of the company's benchtop demonstrator, which is more than double the size of a DVD player, recording and playing back an MP3 music file.
Holograms are formed when two laser beams displaying the same image intersect -- the interference between the beams creates the image in three dimensions. In holographic storage, the beams' intersection creates a two-dimensional "page" of information, holding more than a million individual bits of data, Dhar said. When that page is stored in a light-sensitive material, only a single laser is needed to project the image onto a detector and recover the information much more quickly than current storage devices.
Early efforts at holographic storage required large, complex and expensive collections of lasers and detectors, Dhar said. But today's DVD drives use mass-produced, inexpensive laser diodes powerful enough to record data holographically, and digital cameras include mass-produced, inexpensive detector arrays that can read the data, she said.
What's left, Dhar said, is finding a suitable material for holding the data pages. Early attempts at creating holographic media failed because the substances would distort after storing the image or fail to produce sufficient contrast levels for a detector to pick out the ones and zeros that make up the data, she said. The optimal holographic media, which InPhase is working on with companies such as data storage disc-maker Imation, should be light sensitive enough to store the data quickly, while remaining clear enough to allow data recovery, she said…