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 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 for marketing purposes, since the device has 3 physical dimensions and no exotic higher dimensional properties. The fractal/holographic nature of its data storage is also purely 3-dimensional. The size, orientation and three-dimensional position of the nanostructures make up the claimed five dimensions.