Data storage

Long-term data storage in glass

A team of British researchers has developed a laser writing technique capable of storing large amounts of data in glass.

So-called five-dimensional (5D) data storage uses molecule-sized nanostructures created in silica glass to store information, and is 10,000 times more dense in storage than a Blu-Ray disc.

Credit: Yuhao Lei and Peter G. Kazansky, University of Southampton

“Individuals and organizations are generating increasingly large data sets, creating the desperate need for more efficient forms of data storage with high capacity, low power consumption and long lifespan,” says the Dr Yuhao Lei, researcher at the University of Southampton, UK, and lead author of an article in Optical describing the technique.

The technique can write at speeds of around one million voxels per second, which is equivalent to recording 230 kilobytes of data per second. It’s not particularly fast compared to conventional data storage – a test chip created by the researchers took months to write and then read five gigabytes. But silica is more stable and much denser than other methods, making it useful for information that needs to last.

“While cloud-based systems are designed more for temporary data, we believe that storing 5D data in glass could be useful for longer-term data storage for national archives, museums, libraries or private organizations,” Lei said.

Read more: How to preserve data so it lasts 13.8 billion years

Five-dimensional optical storage is not a new concept, but it was previously not fast enough or dense enough to be a feasible storage method.

Lei and his colleagues improved the technique by using a laser that sends out pulses of light at ultrashort intervals – every femtosecond (10-15 seconds) or more. This laser creates tiny pits in the glass, called nanostructures, ranging in size from 50 to 500 nanometers (less than half the width of a bacterium). By adjusting the way the laser pulsed on the glass, using a phenomenon called near-field enhancement, the researchers were able to create nanostructures more efficiently without damaging the chip.

“This new approach improves data writing speed to a practical level, so that we can write tens of gigabytes of data in a reasonable amount of time,” Lei says.

“Highly localized precision nanostructures allow for greater data capacity because more voxels can be written in a unit volume. In addition, the use of pulsed light reduces the energy required for writing.

Researchers are now figuring out ways to increase write speed and plan to get the technology out of the lab.

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