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Issue One 2014 - Issue #20


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A cheap and secure way to deal with avalanche of data

Story by Mandy Thoo

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edward linacre

The data tsunami has unleashed a wealth of opportunities for scientific research, better medicine and safer banking. Using big data – the vast amount of digital information generated round the world – pharmaceutical companies are developing more personalised medicine, financial firms are improving fraud detection, and scientists are finding more clues to defeat diseases including tuberculosis and cancer.

However, the data deluge has also incurred high costs for companies – and the environment. To cope with the explosion, researchers at Swinburne have developed cheaper, faster, lighter, more secure and environmentally friendly ways of storing and transmitting data.

Big data, big problems

Every phone call, social media post, online search, internet purchase or other web activity is contributing to the 2.5 billion gigabytes of data that humans generate daily. In 2014, we will generate the same amount every ten minutes.

This big data comes with big demands – corporations such as Facebook and Google are spending billions of dollars on infrastructure to store it, with data centres using 1.3 per cent of the world’s electricity each year.

Professor Min Gu, director of Swinburne’s Centre for Micro-Photonics, says that the data accumulated in recent years is just the beginning of the explosion: “The question of where and how to sustainably store and transfer data is an urgent issue, and we need these solutions right now.”

With his research team, Professor Gu – a pioneer and international leading researcher on 3D optical imaging science – has worked tirelessly to overcome the growing problems. Their solution is to manipulate light particles (photons) at a microscopic scale, known as nanophotonics.

Storing a football stadium’s worth of data on one disc

The problem with the magnetic hard disc drives used in most of our computers and data centres is their short lifespan and high energy consumption, Professor Gu says. Data centres have to copy their files into new systems each year, and the process, apart from being costly, also risks losing 20 per cent of the data.

Now, Swinburne researchers have developed a DVD that can securely store one petabyte, or 1000 terabytes. “If a data storage centre of one petabyte is like a football stadium, we can now fit the entire stadium into one DVD,” says PhD student Priyamvada Venugopalan, who has been working on the project.

Venugopalan says that a conventional DVD can only store 4.7 gigabytes of data: “The recording process involves ‘shooting’ laser beams in the form of dots into the disc, which means the storage size is defined by how many dots the disc can fit.”

“So the smaller the laser beam, the more information you can store,” says Professor Gu. “However, physics law dictates that the diameter of this recording beam cannot be smaller than 400 nanometres, and this has been the limiting factor of storage size in DVDs.”

Since smaller individual beams can’t be produced, the researchers have developed a new method to work around the limitation. The technology combines two beams of light: a round-shaped recording beam and a bigger, doughnut-shaped anti-recording beam.

When the two beams are used simultaneously, the doughnut-shaped beam cancels out most of the round-shaped beam, resulting in a recording beam of only nine nanometres, allowing the DVD to store roughly 220,000,000 times the amount of the conventional disc.

“One of the most exceptional features of our newly developed optical storage technique is vast saving in energy consumption,” says Dr Xiangping Li, a research coordinator of this project.

The team has also devised a way to further secure the data, as well as boosting the longevity of the disc. By replacing conventional dye used on the recording layer of discs with graphene, they can now burn holographic signals – that can be used to protect the data – into discs. Using graphene also means the disc is much more resistant to scratches.

Butterfly wings inspire faster data transfer

The Centre has also developed a photonic crystal that mimics the wings of a butterfly. The device, less than the width of a human hair, can greatly improve data transfer speed.

“As our storage of data increases, so does our need to transmit and process it,” says Dr Benjamin Cumming, a postdoctoral researcher working with Professor Gu.

“Light exists as a wave that swings up and down, and they can travel in a spiralling pattern,” Professor Gu says. “In order to send data simultaneously, telecommunications technology uses beam splitters to split light into different directions, and each separate beam carries its own data.”

However, conventional beam splitters only split light into linear – vertical or horizontal – beams because natural crystals used in the device can’t separate left-handed and right-handed light. “But if light can travel in spiralling patterns, we should be able to split it into left-handed, anticlockwise, spirals, as well as right-handed, clockwise, spirals,” says Professor Gu. “To achieve this, we created an artificial crystal based on the blueprint of the green hairstreak butterfly.”

The butterfly, known as Callophrys rubi, contains rows and rows of interconnected coiled springs. Professor Gu says that it’s exactly this structure that allows the artificial crystal to split light into left and right spirals.

“Imagine data as a crowd of people going from one room to another,” he says. “The more doors you open, the more people can get through simultaneously. This is what we hope to achieve – splitting light into other patterns means more data can go through, so data transfer will be faster.

“We can also twist the spirals further, which equates to building wider doors, so we can store more information in each transfer.”

Light-powered future

“If you walk into a data centre, you’ll see stacks and stacks of hard discs lined together,” Professor Gu says. “We envision that future data centres will contain stacks of graphene-based DVDs instead.

“Not only will this greatly improve storage space, it can save a lot of energy – disc storage doesn’t require much electricity, even for decades of storage, because it doesn’t use any power when idle. Also, the graphene-based discs are more resistant to damage, as well as providing better security for the data.”

And as they improve the efficiency of the photonic crystal, the researchers aim to use the device for optic computing. Professor Gu says researchers anticipated the dilemmas of big data a decade ago, and have been discussing how to store and transmit vast amounts of data since then.

“But it wasn’t until four years ago when we had the right equipment, the funding and a team with the skills to manipulate light at a nanoscale.

“We’ve now used light to achieve bigger storage, faster data transmission, and our next step is to improve solar technology. Our vision is to create cheaper, lighter, more secure and environmentally friendly data storage systems, as well as faster and more efficient data transfers, using sunlight to power them all.”

Saving costs for cloud computing

Swinburne researchers are also helping small businesses minimise their cloud computing costs. Dr Dong Yuan, a research fellow in the Centre for Micro-Photonics, says cloud computing is a cost-effective solution for normal applications, such as maintaining a website, but the cost leaps when it comes to ‘big data’. Managing 20 terabytes of data in the cloud, for instance, can incur a yearly cost of $120,000.

“Over 95 per cent of companies in Australia are small businesses, and they provide nearly half of the industry employment in the nation,” Dr Yuan says. “Cloud services can be a huge burden for them if they want to use big data, so we’re keen to help them decrease this cost.”

Working together with ZOYU, a company that builds software on the web, researchers are developing a suite of technologies based on mathematical models. It includes saving storage costs by eliminating unnecessarily duplicated data, determining which data to place together, and replicating data based on popularity.

“If we manage to store related data with the same service in the first place, we can save the cost of transferring data from one cloud service to another. The technology will also replicate popular data, including certain webpages or videos, to save costs for the company when people access them.”

“A lot of programs are already run on the internet, including currency exchange and online purchases,” says Zhuo Liang, managing director of ZOYU. “We predict that all software will be stored and used in clouds in the future, so working with Swinburne researchers is a great opportunity to help small and medium businesses save their cloud costs.”

Big data in numbers

  • 1000 gigabytes or one terabyte can be stored on 210 conventional single-sided DVDs.
  • 100 terabytes is the size of a full 3D imaging of a rat’s brain.
  • 1000 terabytes (One petabyte) is the amount of data the Australian synchrotron generates each month, the same amount of data that Avatar needed to render its 3D CGI effects.
  • 220 million single-sided DVDs or 250 four-terabyte magnetic hard discs are the equivalent of the new DVD storing one petabyte.
  • 30 petabytes of data is currently stored by Facebook. This can be stored in 7500 four-terabyte hard discs, or in three of the one-petabyte DVDs.
  • 1,000,000 petabytes of data currently exist in the digital universe. That’s 2.7 zettabytes and roughly three million of the new DVDs.
  • 35 zetabytes the estimate of data to be generated each year by 2020.

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