5D optical data storage

5D optical data storage (also branded as Superman memory crystal,^[1] a reference to the Kryptonian memory crystals from the Superman franchise) is an experimental nanostructured glass for permanently recording digital data using a femtosecond laser writing process.^[2] Discs using this technology could be capable of storing up to 360 terabytes worth of data^[3][4] (at the largest size, 12cm discs) for billions of years.^[5][6][7][8] The concept was experimentally demonstrated in 2013.^[9][10][11] Hitachi and Microsoft have researched glass-based optical storage techniques, the latter under the name Project Silica.^[12][13]

The "5-dimensional" descriptor is because, unlike marking only on the surface of a 2D piece of paper or magnetic tape, this method of encoding uses two optical dimensions and three spatial co-ordinates to write throughout the material, which suggested the name ‘5D data crystal’. No exotic higher dimensional properties are involved. The size, orientation and three-dimensional position of the nanostructures comprise the so-called five dimensions.^[3]