Optical storage sings the blues

Computerworld - Even IT managers can get the blues. Or at least that's what a gaggle of vendors are hoping as they prepare ultradense optical storage products based on blue-laser technology.

Conventional optical technologies such as CD, DVD and magneto-optical (MO) drives write data using red lasers. But makers of storage systems and recording media are developing ways to read and write using more efficient blue lasers. Because these lasers operate at shorter optical wavelengths, they can write more data in the same space and write and read data faster than devices that use red lasers.

Sony Corp. led the way when a consortium it founded last fall announced Blu-ray, a technology that can write 25GB of data on a DVD-size disc (a standard DVD holds 4.7GB). And Cambridge, England-based Plasmon PLC is already shipping a first-generation blue-laser disc drive that boosts the capacity of a 5.25-in. optical disc from 9.1GB to 30GB. Plasmon says the price per gigabyte of its drive is 80% lower than the prices of products based on conventional red-laser MO technology.

Competing Camps

Most of the buzz about blue-laser technology has focused on the consumer electronics market, where blue-laser discs are seen as a successor to DVDs. The devices could also be used for backing up desktop PCs or archiving audio, video and image files.

Two industry groups are promoting incompatible formats: Blu-ray Disc Founders, a consortium of Japanese companies led by Sony and recently joined by Hewlett-Packard Co. and Dell Inc.; and the DVD Forum, led by Toshiba Corp. and NEC Corp.

The high-definition DVD (HD-DVD) standard promoted by the DVD Forum is an extension of red-laser technology that uses the same disc form as conventional DVDs. Designed to maintain backward compatibility with existing DVD media, it uses the same bonded-disc structure as the current red-laser DVD and sandwiches the recording layer between two 0.6mm-thick plastic layers. A single-layer read-only disc has a capacity of 15GB, and a dual-layer disc supports 30GB.

Plasmon's UDO drive

The Blu-ray standard represents a more radical departure from the existing DVD format. While the disc is the same size as a DVD, the recording layer sits on the surface of a 1.1mm substrate and is protected by a special coating. A single-layer BD-ROM, as the Blu-ray Disc Founders call it, will hold 25GB—67% more than an HD-DVD—and a dual-layer disc will hold 50GB.

Mike Fidler, a senior vice president at Sony, says the company will have Blu-ray media in both write-once and rewritable formats by year's end and will ship a Blu-ray disc player by the end of 2005. Blu-ray in PCs will follow roughly the same schedule, he predicts. "HP and Dell look at this from both the entertainment and data-storage perspectives," he says.