Blu-ray: The next generation of disk

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Data to go

As agencies such as Alcohol, Tobacco, Firearms and Explosives move from 650M of storage per CD-ROM to DVDs that can store 4.7G, the optical-disk industry itself is advancing beyond DVD.

At least three vendors have products based on what they call the next-generation optical disk, the Blu-ray, which can hold up to 50G.

In February 2002, a coalition of nine electronics companies published basic specifications for this new video-recording format. They said they would consider adapting it for data storage as well.

Today's DVD lasers read and write with a 650-nanometer wavelength. Blu-ray uses a bluish, 405-nanometer laser beam'hence the name. The shorter wavelength can fit more information into closer-spaced pits in the disk's data layer.

Blu-ray disks are expected to hold about 27G per disk in either write-once or rewritable format. Researchers have devised ways of placing multiple data layers on a disk, increasing the potential storage density to 50G or more.

The first Blu-ray products will be for video recording, not data storage. Blu-ray recorders are about to arrive on the market from LG Electronics Inc. of Seoul, South Korea; Matsushita Electric Industrial Co. Ltd. of Osaka, Japan; and Sony Corp.

Just as VHS battled with the Betamax format for dominance in the videocassette market in the early 1980s, so will the post-DVD optical disks entangle users in format wars.

Toshiba Corp. and NEC Corp. have endorsed a competing technology called Advanced Optical Disk, or AOD, storing 15G per disk.

AOD doesn't have as much industry support as Blu-Ray, but the DVD forum, an industry group, has chosen the AOD read-only format over Blu-ray as the successor to DVD. AOD products are expected to hit the marketplace in early 2005.

About the Author

Joab Jackson is the senior technology editor for Government Computer News.


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