After Hours

Holographic media: A future backup media candidate?

Recently, I've been looking at the various technologies for

backing up data. In addition to the previously discussed optical

media solutions and online

backups, one technology undergoing heavy development (pointed out to me by

a colleague) is that of holographic media. Holographic media is a next-generation

optical storage candidate. Forget HD-DVD and Blu-ray—the huge potential of HVD

puts them to shame. A single DVD-sized HVD disc could potentially store 3.9

terabytes; that’s 6000 CDs, 830 DVDs, or 160 Blu-ray discs! This definitely surpasses

the high-volume storage capacity offered by magnetic tapes!

How does HVD

work?

Blu-ray and HD-DVD get more data on to a disc than conventional DVD

by using a shorter wavelength of light to cram more data in the same space. HVD

actually uses two lasers (green and red) and two layers on the disc. The bottom

layer is much like the metal film layer of a DVD-R—this contains servo

information picked up by the red laser. The green laser deals with data storage

on the upper layer. Between these two layers, a dichroic mirror layer reflects

the green laser while allowing the red laser through. While current optical

media store 1-bit per pulse, HVD hopes to increase this to 60,000-bits per

pulse! The HVD alliance

web site gives some more detailed information for anyone who’s interested in

exactly how this is achieved.

Although we’re a long way from seeing HVD in daily use—some

rapid progress is being made. Optware

are set to release a 30-GB holographic card before the end of 2006—the media

will cost around $1 USD, reader devices should come in at roughly $1700, with a

reader/writer setting you back over $8000. The drive prices can be compared to those

of DVD-R in the late 90’s; blank media, however, seem to be much cheaper. The

current cutting edge formats, Blu-ray and HD-DVD, have just started to become

economically viable for daily use. Read/write drives are currently around the

$1000 mark with media coming in at around $30. Some, however, are describing

these as transitional formats, claiming

that they will not enjoy as great a lifespan as current DVD formats due to the

rapid development of HVD and other high volume holographic technology. Whether

this is the case or not will remain to be seen. A great deal of money has been

invested in Blu-ray and HD-DVD; manufacturers will likely want to see as much

return on their investment as possible.

Whatever the short-term outcome, holographic storage will probably

become the norm, just as DVDs are at present. Whether this media can be used

for long-term data archiving will still depend on the stability of the media. The

huge capacity does overcome this in some manner—re-writing a few 4TB discs

annually would be much more acceptable than 800-fold, if DVD media was used!

What are your opinions on next generation optical media?

Will we see the lifespan of new formats decrease and a rapid development of new

or will this be artificially slowed to give consumer markets a chance to keep

up, as well as increase profits for technology companies? Have you started to use

Blu-ray or HD-DVD? If not, do you plan to?

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