Professor Min Gu and Dr Xiangping Li of Swinburne University, along with a visiting PhD student from Taiwan's National Chiao Tung University, have found a way of using gold nanorods as a coating on DVDs.
As the light beam is polarised in different directions, it is reflected by different subsets of the nanorods. Different light frequencies (colours) can also be used.
"Instead of having a beam in a straight plane (a vector), the team has been able to make that beam rotated on any plane, with infinite control so now they can make that beam polarised in any direction and then they can tune the light frequency," said Professor Gu.
In addition to increasing storage density (the length of a gold nanorod is 1/500th of the thickness of a human hair), the technique provides a new way of encrypting the data.
The technology is said to have medical applications in the use of lasers to destroy cancer cells.
The research was funded by the Australian Research Council.