More data storage? Here's how to fit 1,000 terabytes on a DVD

Jun 20, 2013 by Min Gu, Yaoyu Cao & Zongsong Gan, The Conversation
Using nanotechnology, researchers have developed a technique to increase the data storage capacity of a DVD from a measly 4.7GB to 1,000TB. Credit: Nature Communications

We live in a world where digital information is exploding. Some 90% of the world's data was generated in the past two years. The obvious question is: how can we store it all?

In Nature Communications today, we, along with Richard Evans from CSIRO, show how we developed a new technique to enable the data capacity of a single DVD to increase from 4.7 gigabytes up to one petabyte (1,000 terabytes). This is equivalent of 10.6 years of compressed high-definition video or 50,000 full high-definition movies.

So how did we manage to achieve such a huge boost in data storage? First, we need to understand how data is stored on optical discs such as CDs and DVDs.

The basics of digital storage

Although optical discs are used to carry software, films, games, and , and have great advantages over other recording media in terms of cost, longevity and reliability, their low data storage capacity is their major limiting factor.

The operation of is rather simple. When you burn a CD, for example, the information is transformed to strings of (0s and 1s, also called bits). Each bit is then laser "burned" into the disc, using a single , in the form of dots.

The storage capacity of optical discs is mainly limited by the of the dots. But as there's a limit to the size of the disc as well as the size of the dots, many current methods of data storage, such as DVDs and Blu-ray discs, continue to have low level .

To get around this, we had to look at light's .

Credit: Adam Foster, Codefor

Circumnavigating Abbe's limit

In 1873, German physicist Ernst Abbe published a law that limits the width of .

On the basis of this law, the diameter of a spot of light, obtained by focusing a light beam through a lens, cannot be smaller than half its wavelength – around 500 nanometres (500 billionths of a metre) for visible light.

And while this law plays a huge role in modern optical microscopy, it also sets up a barrier for any efforts from researchers to produce extremely small dots – in the nanometre region – to use as binary bits.

In our study, we showed how to break this fundamental limit by using a two-light-beam method, with different colours, for recording onto discs instead of the conventional single-light-beam method.

Both beams must abide by Abbe's law, so they cannot produce smaller dots individually. But we gave the two beams different functions:

  • The first beam (red, in the figure right) has a round shape, and is used to activate the recording. We called it the writing beam
  • The second beam – the purple donut-shape – plays an anti-recording function, inhibiting the function of the writing beam

The two beams were then overlapped. As the second beam cancelled out the first in its donut ring, the recording process was tightly confined to the centre of the writing beam.

This new technique produces an effective focal spot of nine nanometres – or one ten thousandth the diameter of a human hair.

The technique, in practical terms

Our work will greatly impact the development of super-compact devices as well as nanoscience and nanotechnology research.

The exceptional penetration feature of light beams allow for 3D recording or fabrication, which can dramatically increase the data storage – the number of dots – on a single optical device.

The technique is also cost-effective and portable, as only conventional optical and laser elements are used, and allows for the development of optical data storage with long life and low energy consumption, which could be an ideal platform for a Big Data centre.

As the rate of information generated worldwide continues to accelerate, the aim of more in compact devices will continue. Our breakthrough has put that target within our reach.

Explore further: New microscope collects dynamic images of the molecules that animate life

More information: www.nature.com/ncomms/2013/130… full/ncomms3061.html

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User comments : 29

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jalmy
1.7 / 5 (12) Jun 20, 2013
Dope! When can I buy one at Newegg for <50$?
tscati
5 / 5 (1) Jun 20, 2013
and how long will it take it write a petabyte?
CapitalismPrevails
2 / 5 (20) Jun 20, 2013
Great. Now the National Storage Agency(NSA) can save even more blackmail information about us for longer periods of time.
VendicarE
2.8 / 5 (11) Jun 20, 2013
CapitalismPrevails is right. Ronald Reagan never should have started the program of digitally spying on the phone calls and other electronic communication of Americans.
winthrom
5 / 5 (3) Jun 20, 2013
I guess this means that holographic movies on DVDs are soon practical.Princess Leah coming from a droid is on the way!
beleg
1.6 / 5 (7) Jun 20, 2013
Highest tech polymerization.
fmfbrestel
5 / 5 (2) Jun 20, 2013
Just looked at the source journal article (free full article through the link), looks pretty legit. Take a while for consumer products, but major data centers, and organizations needing large scale data archives are going to eat this up!

Also, pair this breakthrough with this:http://phys.org/n...ors.html

(laser disk writers as super-capacitor fabricators)
Mike_Massen
2 / 5 (12) Jun 20, 2013
winthrom might not realise just what they uttered...LOL
I guess this means that holographic movies on DVDs are soon practical.Princess Leah coming from a droid is on the way!
:-)
Given the rise of organic and soft robotics to ensure various forms of 'pleasant companionship' your last sentence above could be taken in a 'far wider context',

*grin*

Golly Gee Willikers, the read/write rate may well be the killer in the short term, obviously in the long term arrays of minuscule organic die lasers each the size of a 'speckle' could multiply this a thousand fold !
baudrunner
1.8 / 5 (10) Jun 20, 2013
And if you overlap the two donut shaped beams to create a Venn Diagram type region in the middle you can increase the storage even more, by multiples, depending on the precision of the recording device, if you can somehow block out or rewrite over the lagging space in the one donut ring.
DonGateley
1.8 / 5 (6) Jun 21, 2013
I see locating/tracking to be a central problem in deploying this. What kind of actuators do we have that can resolve these distances?
scenage
3.5 / 5 (2) Jun 21, 2013
I'm with Don,

It's great that we can store it, how on earth will we read it with speed?
NeutronicallyRepulsive
1 / 5 (2) Jun 21, 2013
I have to admit, I do care more about longevity of data persistence than about capacity. Don't get me wrong, capacity is good, but I'd rather like that million-year disk (it could be actually just hundred or thousand year, but oh well).
Skepticus
1.4 / 5 (9) Jun 21, 2013
I have to admit, I do care more about longevity of data persistence than about capacity. Don't get me wrong, capacity is good, but I'd rather like that million-year disk (it could be actually just hundred or thousand year, but oh well).

I don't think we will have millenniums or eons-long lasting storage device unless we have a culture, a systems of belief or a form of government that is extremely long lived. Too many times historical legacies are burned, smashed to bits or burned already by the whims of the fanatics of the day.
aroc91
5 / 5 (2) Jun 21, 2013
CapitalismPrevails is right. Ronald Reagan never should have started the program of digitally spying on the phone calls and other electronic communication of Americans.


And Obama shouldn't have let it continue. Blame lies with both parties.
jalmy
1.8 / 5 (10) Jun 21, 2013
I have to admit, I do care more about longevity of data persistence than about capacity. Don't get me wrong, capacity is good, but I'd rather like that million-year disk (it could be actually just hundred or thousand year, but oh well).


There is no reason to think that in 50 years we wont be able to store a terabyte of data on a grain of said that lasts forever unless destroyed by something. So why do you need something that will last that long? It will be ridiculously obsolete in just 1-2 generations anyways.
Sanescience
2.1 / 5 (7) Jun 21, 2013
Soon enough storage will involved lasers that scan over a volumetric medium via solid state actuators for far faster and accurate read/write access. Much more so than physically spinning the media and a motorized read/write head.

animah
5 / 5 (1) Jun 22, 2013
Information density - a 50-gram petabyte device is cool, but a nanomachine that can store its programming at its own physical scale is way cooler.

Injectable cancer-hunter bot anyone?
antigoracle
1.5 / 5 (10) Jun 22, 2013
I have to admit, I do care more about longevity of data persistence than about capacity. Don't get me wrong, capacity is good, but I'd rather like that million-year disk (it could be actually just hundred or thousand year, but oh well).

You'll be pulling the hairs of your head trying to find a drive to read that data then.
TheKnowItAll
1.6 / 5 (7) Jun 22, 2013
I don't think speed will be much of an issue. Smaller dots means more of them can be read/write with less energy per revolution. Odds are the drive will be waiting for the computer to catch up.
Andrew Palfreyman
1.4 / 5 (9) Jun 23, 2013
It's still a long way to the bottom. The holographic theory of spacetime says that each square millimetre of space is capable of storing 10^51 TB.
antialias_physorg
4.2 / 5 (5) Jun 23, 2013
how on earth will we read it with speed?

If nothing better comes along then we'll read it in parallel (using several read heads) - which is feasible for read-only material (like DVD)

What kind of actuators do we have that can resolve these distances

With stuff like this:
http://www.nanomo...otor.htm
I once was in a project with this company. These motors are amazing. Back then (2001) they had 10nm resolution and are now down to 'atomic' resolutions. At decent speeds and huge range (2cm...which is more than 5 orders of magnitude!)

The guy running the company showed us a full 3 axis setup for an atomic force microscope that would fit into the palm of your hand. It didn't even need any vacuum chamber/vibration suppression, since the vibration susceptibility goes with the third power of size. Jaws dropped around the table, I can tell you.
Urgelt
5 / 5 (1) Jun 24, 2013
It's a clever approach. I hope it scales inexpensively for commercial purposes.

And yet, we're still limited to:

- Flat plane recording.

- Binary.

I can imagine - but not design, not my area of expertise - a 1 nm read-write process occurring in a three-dimensional material with non-binary data bits.

With a resolution of 1 nm, and the prospect of working with non-binary bits and in three dimensions, I can't see any reason to think that we're anywhere near any sort of limit on improving storage densities.

Or so I hope.
sirchick
5 / 5 (1) Jun 27, 2013
Question, can this apply to computer hard drive space? I do wonder how long it would take to go through the entire disc to find a given file when its that large without massive RPM?
antialias_physorg
3 / 5 (2) Jun 27, 2013
I do wonder how long it would take to go through the entire disc to find a given file

To find a given file - not long (since that is done by searching the file allocation table - and not by stepping through every bit on the disc)

Searching for a file which has a particular bit of content could take a while. But if the main use of such a storage type is bulk media (e.g. 3D movies) then such searching isn't much of an issue.
Searching within a file is mostly only relevant for plaintext (or compressed plaintext) files - and those take up relatively little space. It's hard to imagine filling up such a motherhuge drive with (unindexed) plaintext.
dev2000
3 / 5 (2) Jun 27, 2013
really great discovery.. now after some thought I can conjecture a way to achieve <1 nanometer
Mike_Massen
1.5 / 5 (8) Jun 27, 2013
dev2000 mused
really great discovery.. now after some thought I can conjecture a way to achieve <1 nanometer
Well indeed, based upon the paradigm described, just scale up the frequencies which reduces the wavelengths. The question arises will the media survive the higher energy photons !
antialias_physorg
3 / 5 (2) Jun 27, 2013
now after some thought I can conjecture a way to achieve <1 nanometer

Problem being that at that scale you run into the size of single atoms (which is about 0.1nm). So not much more room to optimize
Neinsense99
1 / 5 (8) Jul 28, 2013
I have to admit, I do care more about longevity of data persistence than about capacity. Don't get me wrong, capacity is good, but I'd rather like that million-year disk (it could be actually just hundred or thousand year, but oh well).

You'll be pulling the hairs of your head trying to find a drive to read that data then.

Won't the magical market forces ensure that some company will keep making the same drive for centuries just in case? (sarcasm)
Proka Pronalazac
1 / 5 (6) Aug 02, 2013
Can technology based on fractals raise up that number from 1000 tera to 1000 yotabytes of data?