Want to make sure you back something up indefinitely? Then you could do worse than a digital data storage technique that uses laser light to store 360 terabytes of information on nanostructured quartz for up to 14 billion years. Developed by researchers at Southampton University in the UK, the technique uses femtosecond laser pulses to write data in the 3D structure of quartz at the nanoscale. The pulses create three layers of nanostructured dots, each just five microns above the other. The changes in the structure can be read by interrogating the sample with another pulse of light and recording its polarisation — the orientation of the waves — after it's passed through.
The team has now written a series of major works to small glass discs — including the Universal Declaration of Human Rights, Newton's Opticks, the Magna Carta and the Kings James Bible. The density of the data aboard these discs suggests that they could squeeze a total of 360 terabytes onto a single piece of quartz. They also point out that the data is extremely stable: It could endure for as long as 13.8 billion years at temperatures up to 176C.
The idea of archiving data in this way has been around for a little while, but until now the density of data storage has been modest. Back in 2012, a similar technique was used to store 6.2MB per square centimetre — approximately the same density of a music CD. The new advance, though, makes the technique a genuine means of archiving vast quantities of information in perpetuity.