Holographic storage products developed

Emtech: GE is showing off 1TB DVD-sized disks.

Holographic technology has been developed that can pack 1TB onto a DVD-sized disk that can be read by a slightly modified Blu-ray drive and is expected to last 100 years.

The first products using the technology will be 1TB or multi-terabyte drives for archival storage and will hit the market in two to three years, said Peter Lorraine, manager of the applied optics laboratory at General Electric at the EmTech conference in Boston this month.

Consumer drives will appear about two or more years later. "We think there is consumer fatigue over changing formats. Blu-ray has two to four years of life to go. After that, consumers will be clamouring for terabytes of storage."

GE is licensing the technology to other companies rather than manufacturing devices itself. "We will be making an announcement about licensees shortly," Lorraine said.

The holographic drives have an access time of 3ms and data transfer rates up to five times faster than a DVD. And they can be factory replicated, making them suitable for ultra-high quality movie distribution.

Holographic technology has been around for 30 years and many companies have tried to bring products to market. The major problems have been the cost of the drives, the need for tight tolerances, and sensitivity to ambient conditions.

Lorraine says GE has essentially solved these problems.
Holographic drives work by splitting a laser beam into a reference beam and a signal beam, which is encoded with data. The two beams are then crossed to produce an interference pattern that is stored. Older versions stored 'pages' of a million bits, stacked ten thousand deep at hundreds of locations on a disk.

Researchers looked at what would happen if they reduced the page size to a single bit. It turned out that these 'micro holograms' could store as much data per unit area but were far easier to read. In fact the upper data layers can be read by a standard Blu-ray player, and all layers can be accessed by slightly increasing the tracking range of the read head and making a minor adjustment for spherical aberration.

The major issue in making it work turned out to be choosing the right storage medium, which is where Lorraine says GE has made its breakthrough.