14 DAY TRIAL // The University of Berlin in partnership with several other universities managed to store 500GB of data on a regular HD DVD, also known as Blu-ray disc. The project, named Microholas, started as an experiment searching for new recording techniques, using nanostructures inside the disk rather than on the surface, as conventional optical systems use.
A single-layer Blu-ray Disc can hold 25GB, a dual-layer disc holds double. Single- and dual-layer HD DVDs hold 15GB and 30GB of data, respectively and the current storage crown for a commercial disc goes to Sony with their dual-layer Blu-Ray disc able to store 50GB of data. The 500GB prototype has 50 data-storage layers with a very complex internal structure.
The Register reports that the Microholas project (short for Microholographic Data Disk for Archival Storage) achieved such a feat by developing a "microholographic recording surface using nano structures inside the disk rather than on the surface as in conventional optical storage systems".
This involves going beyond just storing data on the surface of the disc; instead, going 3D and using nano structures as well, the technique being known as "holographic multiplexing" is the key which allows storage to be done on tracks that overlap, therefore ensuring far greater storage potential. Professor Susanna Orlic told German site Pressetext that even greater storage densities can be achieved, the project's aim being that of reaching one terabyte (1TB) of data stored on a single disc by 2010.
From its home page an interested visitor can find out the general objectives and aims of the Microholas project: "The overall objective of MICROHOLAS is to implement the microholographic technique for optical storage on CD/DVD-like disks for digital data. The project aims at long term storage by utilizing periodic nano structures in the disk volume rather than on the surface as in conventional optical storage systems."