Recently, I’ve been looking at the various technologies for
backing up data. In addition to the previously discussed optical
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; thats 6000 CDs, 830 DVDs, or 160 Blu-ray discs! This definitely surpasses
the high-volume storage capacity offered by magnetic tapes!
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-Rthis 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 whos interested in
exactly how this is achieved.
Although were a long way from seeing HVD in daily usesome
rapid progress is being made. Optware
are set to release a 30-GB holographic card before the end of 2006the 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 90s; 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 mannerre-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?