Researchers from Swinburne University have overcome the limit of a physics law around optical data storage to increase DVD capacity to 1000TB.
Transferring data to optical discs relies on strings of binary digits, with each 0 or 1 bit burned onto discs via lasers to form ‘dots’. How much information can fit on a disc is limited by the size of each dot – the smaller the dot, the greater the storage capacity.
The law limiting the size of these dots was first found by German physicist Ernst Abbe in 1873, which dictated that a light beam could not produce a focal spot smaller than 500 nanometres for visible light.
However, Swinburne researchers have managed to circumvent the law by using a two-light-beam method with different colours.
While the two beams alone cannot produce dots smaller than Abbe’s law, when they are used together in an overlapping sequence, the size of dots can be reduced to just nine nanometres. In practical terms, this means a DVD’s storage capacity can be increased from 4.7GB to 1000TB.
“If we apply this technology into optical recording, we can produce a DVD with a capacity which is 10,000 times higher,” said Professor Min Gu, director of the Centre for Micro-Photonics at Swinburne University of Technology.
Gu and his team of up to 15 researchers have been working on optical data storage for more than 10 years. He said previously other researchers have been deterred from trying to overcome Abbe’s law because it seemed impossible, and the breakthrough has not been without its challenges.
“We had to do a lot of things, of course. We had to work on the laser, and we also had to invent new material. By combining the new material and the new way of using lasers, we could achieve this breakthrough,” he said.
While most people would typically associate disc storage to CDs and DVDs, the technology has much greater benefits than storing music and movies. For example, using fewer discs to store a greater amount of information could have energy saving benefits for data centres.
“(You) can save up to 90% of energy for recording 1 bit information,” Gu said.
“If you have a data centre and a 90% saving, that’s a huge saving.
“(In the future), information will increase by magnitudes, so if we’re going to use all the energy to recall the information, optics can eventually solve the problem.”
Energy saving for data centres is becoming an increasing concern around the world. According to the DatacenterDynamics 2012 Global Census, the power needs from global data centres increased by 63% between 2011 and 2012.
Additionally, as electricity prices around the world increase, the new optical data storage breakthrough could be a boon for companies as big data becomes more widely used. Already, companies such as Facebook’s spin-off company Optical Archive Inc and Sony have expressed interest in Gu’s research.
He expects a product could be released to the market in five years.
Now the team at Swinburne is working on a number of engineering issues, such as reducing the size of the product, which currently measures around 1m x 1m. Gu hopes to decrease this to 20cm x 20cm.
The team is also working on integrating the electronics and developing a longer life recording-medium. He said currently the life of hard drives is only three to five years, but optical disc-life could increase to 100 years.
“So there are a lot of material engineering problems that we also have to solve in order to get a prototype. But we are actively working with industry partners and trying to work on this commercialisation,” Gu said.
Commercialisation agreements have yet to be signed by the research team, but Gu said there have been a couple of proposals, including from an investor in China.
In an ideal world, he would like to see the Australian government provide funding for the research to allow it to stay in Australia, such as through a university spin-off company.
There is also interest from the public in the technology, with the Swinburne University of Technology team recently winning the Knowledge Commercialisation Australasia People’s Choice category in the Research Commercialisation Awards.
Dr. Yaoyu Cao, a research fellow involved in the breakthrough, said the award will hopefully set up further opportunities to develop commercial products.
“The development of next-generation optical data storage techniques for big data needs a great deal of support from diverse industry partners, such as the IT and the electronics industries,” Cao said.
“Secondly, the award can help society recognise the significance of developing next-generation energy-saving optical data storage techniques for big data in the era of an information boom. This understanding can attract broader communities to take part in transforming the data storage schemes in the future.”
[Image: (L-R) Prof. Min Gu, Dr. Xiangping Li and Dr. Yaoyu Cao.]