http://www.sciencealert.com/news/20140309-26116.html
But Dr Zongsong Gan, a researcher at Swinburne University of Technology in Melbourne, Australia, has found a revolutionary way we can fit a whole lot more data onto traditional optical storage devices, such as CDs, and is now using that technology to help data storage keep up with demand.
This advance required them breaking a physical barrier known as the diffraction limit of light. Light cannot be split any smaller than around 500 nanometres, and before their work it was thought that, because of this, light wasn't capable of writing bits of information smaller than 500 nanometres across.
But by using two-light-beams with different abilities, the scientists managed to whittle down the point of light writing the data to just nine nanometres across, or one ten thousandth the diameter of a human hair.