5D optical data storage

5D optical data storage (also branded as Superman memory crystal, 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. Discs using this technology could be capable of storing up to 360 terabytes worth of data (at the largest size, 12 cm discs) for billions of years. The concept was experimentally demonstrated in 2013. Hitachi and Microsoft have researched glass-based optical storage techniques, the latter under the name Project Silica.

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.