Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Video disks ditch binary storage

Next-generation disks could hold hundreds of hours of footage.

Hundreds of hours of video could be squeezed onto one disk, but TV companies are unlikely to take advantage of the technology. Credit: © getty

Why count in binary when you can use hundreds of different digits at once? That's the principle that has allowed British physicists to develop a video disk that stores far more data than has ever been possible before.

The disk, called MODS, for Multiplexed Optical Data Storage, could easily store all 350 episodes of The Simpsons, with room to spare for some Futurama too. A double-sided version of the disk could potentially contain 472 hours of video footage - equivalent to a terabyte, or 1,000 gigabytes, of data.

This would dwarf the capacity of DVDs, currently the most widely used video storage medium, says Peter Török of Imperial College London, whose team is developing the new technology. A double-sided, double-layered DVD holds less than 20 gigabytes of data.

And it's ten times as much as the most advanced technology so far: BluRay disks, which are to be commercially released shortly, can hold a maximum of 100 gigabytes.

In the groove

DVDs and compact disks store their information in the form of a microscopic groove pitted with tiny ledges and troughs. When the groove is scanned with a laser, the boundaries between these two levels create specific patterns in the reflected beam that are then converted into sound or picture information.

This is a purely binary system - any point in the groove is either on a ledge or in a trough. This limits the amount of information that can be etched into the groove. Even using optical tricks such as reducing the wavelength of the laser light, as BluRay technology does, can't squeeze more than about 25 gigabytes into a single layer of data.

So Török's team decided it was time to expand their disks' vocabulary. They created a groove with troughs sunk at any one of 332 different angles - equivalent to counting with 332 digits instead of just 2, or spelling with 332 different letters instead of just a and b.

The team squeezed ten times more data onto a disk of the same size, Török reported today at the Asia-Pacific Data Storage Conference 2004 in Taoyuan, Taiwan.

So far the researchers can't retrieve information from their disk fast enough for video footage. "We don't yet have a machine where you can put the disk in and play Charlie's Angels," Török says.

But he believes that MODS disks could hit the shops between 2010 and 2015. There's bad news for anyone hoping to hold the complete collection of The Simpsons in the palm of their hand, however. "If you put all of The Simpsons on a disk you would have to sell it for $10,000," Török says. "Could you bear that thought?"

Although the marketing men would prefer their comedy shows to be doled out in smaller batches, MODS disks might be useful for libraries or software companies looking for ways to marshal their huge amounts of data. "The British Library could put all their microfiches onto disks," Török suggests. "It will be very good for archiving."


Related links

Related links

Related external links

Imperial College Photonics Group

How DVDs work

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Hopkin, M. Video disks ditch binary storage. Nature (2004).

Download citation

  • Published:

  • DOI:


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing