Superman memory crystals could store data for billions of years
The scientists from the University's Optoelectronics Research Centre (ORC) have developed the write and read processes of five dimensional (5D) digital data through femtosecond laser writing, where they use short bursts of high intensity light to encode a quantum bit, (a qubit) through the polarization of a single photon.
The self-assembled nanostructures in the glass (which is fused quartz) change the way light travels through it, modifying polarization of light that can then be read by combination of optical microscope and a polarizer, similar to that found in Polaroid sunglasses.
The researchers call the nanostructured glass "Superman memory crystal," as the glass memory has been compared to the "memory crystals" used in the Superman films.
"The information encoding is realized in five dimensions: the size and orientation in addition to the three dimensional position of these nanostructures," the researchers said in a news release.
The orientation of the photon or dot (horizontal or vertical) determines whether it has a bit value of 1 or 0. The dots appear as visible vortices (voxes) in the glass under a microscope.
The storage method enables up to 360TB of capacity on a disc about one-inch in diameter that can withstand temperatures of up to 1,000 degrees Celsius and has a virtually unlimited lifetime at room temperature (13.8 billion years at 190 Celsius). Data is written to a file comprised of three layers of nano-structured dots separated by five micrometres (a micron is one millionth of a meter). The technology was first demonstrated in 2013 when a 300 kilobit digital copy of a text file was successfully recorded in 5D.
"The laser beam was focused 200 [microns] below the surface of a 2 mm thick fused silica sample, which was mounted onto [an] XYZ linear air-bearing translation stage system [from Aerotech Ltd.]," the researchers stated in a paper.
"As a very stable and safe form of portable memory, the technology could be highly useful for organizations with big archives, such as national archives, museums and libraries, to preserve their information and records," the researchers said.
The technology has already allowed major documents from human history such as the Universal Declaration of Human Rights (UDHR), Newton's Opticks, the Magna Carta and the Kings James Bible, to be saved as digital copies "that could survive the human race," the researchers said.
A copy of the UDHR encoded to 5D data storage was recently presented to the United Nations Educational, Scientific and Cultural Organization (UNESCO) by the ORC at the International Year of Light closing ceremony in Mexico in December.