At first HD-DVD looked to be the front runner even though it offered the smallest increase of maximum storage capability (30GB) over standard DVD (9GB), but then Blu-Ray came around and decided to support WMV and so with its larger storage capacity (50GB – with future plans of 100GB discs) it appeared to take the lead – at least in performance.
Well HVD now appears ready to obliterate both of these formats, at least in regards to performance.
How so? Well to start HVD discs have already been demonstrated with 200GB storage capacity, with 1TB discs expected to be developed very shortly. (that is equivalent to 100 dual layer DVDs, 35 HD-DVDs, and 20 Blu-Ray DVDs) On top of its massive storage capacity, HVD also offers transfer speeds greater than 1GB per second – 40 times that of standard DVD. It doesn’t end there. There are already plans for a 4TB disc which would be enough storage capacity to have nearly 1000 movies in 480p, or about 200 movies in HD on one disc.
So what is HVD and how does it differ from the other optical discs?
HVD stands for Holographic Versatile Disc. The technology behind HVD is based on Optware's exclusive servo system and CHDSS (Collinear Holographic Data Storage System) which Hideyoshi Horimai, founder of Optware Corp., originally developed back in 1999.
Collinear holography uses a 532-nanometer green laser to read holographic data on a disc. The light from the laser is split into two beams. Data to be recorded is encoded onto one of the beams while the other beam is used as a reference. The two beams interfere with each other inside the disc's recording layer, thus creating a three-dimensional hologram composed of data fringes, and in this way data is stored.
HVD is the same size of a standard DVD (12cm):
If you look closely at the surface of a HVD disc you can see multiplexed holographic data patterns along the tracks:
The disc structure starts with a substrate with a preformatted pitted aluminum top layer. This is used to store servo data and is read by a red laser. This enables accurate tracking of the disc. A dichroic mirror is laid on top of that with a small gap between it and the next layer which is a photo polymer and where the data is recorded. The mirror reflects the green laser but is transparent to the red laser. In this way it is able to stop the scattering of light within the disc that would otherwise cause noise and deteriorate the signal quality. The last layer is a protective substrate.
Now for those that think this is only vaporware, make no mistake about it – this is a very real technology with working models being demonstrated over the last few months. The first demonstration of both a recording and playback of a HVD disc was back in August of last year.
To further emphasize how real this technology is, back in January the Ecma created a technical committee (TC44) to develop a standardization strategy for Holographic Information Storage (HIS) systems and HVD.
Just this week six major companies announced that they had formally created the HVD Alliance in order to advance the development of HVD and promote it throughout the marketplace.
The companies that currently make up the HVD Alliance are:
- CMC Magnetics
- Nippon Paint
- Pulstec Industrial
- Texas Instruments
- Micron Technology
- InPhase Technologies
As for estimated costs, last year Optware suggested that they were going to initially offer HVD for enterprise and developmental applications for about $20,000 and about $100 per disc. They also said they expect to offer a consumer HVD product by 2007 for under $3,000.