The file is written into a block of quartz by a femtosecond laser as three layers of nano-structured dots .
“The self-assembled nano-structures change the way light travels through glass, modifying polarisation of light that can then be read by combination of optical microscope and a polariser,” said the University. “The information encoding is realised in five dimensions: size and orientation in addition to the three dimensional position of these structures.”
With individual features smaller than a wavelength, the structure behaves as a uni-axial optical crystal with negative birefringence on the macroscopic scale. Retrieval is by quantitative birefringence measurements.
Claimed capacity is 360TB per disc, with survival up to 1,000°C.
The technology was first demonstrated in 2013 when a 300kbit file was recorded. Since then, Newton’s Opticks, Magna Carta and the Kings James Bible have been stored in quartz.
The technology is being presented at The International Society for Optical Engineering Conference in San Francisco this week in the invited paper ‘5D data storage by ultrafast laser writing in glass‘.
Industrial partners are sought by the ORC.