CD with 150 gigabyte capacity(!)
At the "LASER 2001 - World of Photonics" trade show in Munich, the Optical Institute of the Technical University in Berlin introduced the micro-holographic disk with a storage capacity of over 150 gigabytes. Using a microscopic reflective matrix, information can be stored on both surfaces as well as within the disk itself.
According to a report by TU Berlin, with laser beams of varying wavelength and spatially overlapping layers of micro-grids, the disk is rendered in three dimensions. Storage capacity of the micro-holographic CD is equivalent to the amount of space available on 230 standard CDs of 650 megabytes each.