New technique can fit 1000 TB on a single optical disc

Discovery News : To store data on optical discs such as a DVD or BluRay, a near-IR laser burns a mark representing either a 1 or a 0 into the material. The size of the mark is half the wavelength—near-IR is between 750 and 1400 nm—of the laser. This limits the number of marks that can be made, which also limits the amount of data that can be stored—about 4.7 GB on a DVD and 50 GB on a BluRay. Min Gu of Swinburne University in Australia and his colleagues have developed a technique that increases that storage capacity drastically. In addition to the usual near-IR laser, they added a laser using a violet wavelength that interfered with the first laser. The interference shrank the size of the mark that could be burned down to just 9 nm. Because the lasers are very similar to those that are already available, the new high-capacity lasers won’t require commercializing any new technology to go to market.