A new method of recording is set to drastically increase the capacity of a DVD-sized disc, according to researchers from the Centre for Micro-Photonics, based at the Swinburne University of Technology in Melbourne. Peter Zijlstra, James Chon and Min Gu published their findings in a recent edition of the scientific journal, ‘Nature’ and claimed 1.6 Terabytes of data could be squeezed onto one disc.
The paper was titled ‘Five-dimensional optical recording mediated by surface plasmons in gold nanorods’ and explained how the gold nanorods had unique optical properties, which vary with the colour and polarisation of incoming light. Zijlstra’s team claimed to have exploited these features to achieve optical recording.
Both the polarisation of light and its wavelength are used to selectively reshape gold nanorods in a polymer matrix, which is capable of recording nine independent bits in the same focal volume.
To read out the recording, the authors used two-photon luminescence, which allows non-destructive and cross-talk free detection due to its high wavelength and angular sensitivity compared to conventional linear detection. Recording was demonstrated in 10 closely spaced layers, resulting in a storage capacity of 1.6 terabytes per DVD-sized disc. This is already 32 times the capacity of a dual-layer Blu-ray disc but the researchers claim, further reduction of the layer spacing could potentially increase the disk capacity to seven terabytes.