FIVE DIMENSIONAL DVD
Abstract:
Five dimensional DVD is an optical sto-rage device which can store 1.6 Terabytes of data, which is 300 times more than that a single ordi-nary DVD can hold. The name came from the fac-tor that it utilizes 5 dimensions to store data. The five dimensions include 3 spatial dimensions, col-our dimension and polarization dimension. The invention of 5-D DVD explores the possibilities of increasing data density beyond 1 Tbits/cm². The technology makes use of extremely tiny (nanome-ter-scale) gold particles called “nanorods” as the recording medium. The gold nanorods add a new dimension to the current 3 spatial dimensions em-ployed in DVD writing. The nanorods when hit by a controlled light provides a multi wavelength or coloured laser effect, different from the single wavelength approach to read optical discs.
I. INTRODUCTION
Scientists have unveiled new DVD technology that stores data in five dimensions, making it possible to pack more than 300 DVDs onto a single disc. A team of researchers at the Swinburne University of Techn-ology in Melbourne, Australia, have used nanotech-hnology to boost the storage potential nearly 10,000-fold compared to standard DVDs
Multiplexed optical recording provides an un-paralleled approach to increasing the information density beyond 1012 bits per cm3 (1 Tbit cm-3) by storing multiple, individually addressable patterns within the same recording volume. Although wave-length, polarization and spatial dimensions have all been exploited for multiplexing, these approaches have never been integrated into a single technique that could ultimately increase the information capa-city by orders of magnitude. The major hurdle is the lack of a suitable recording medium that is extremely selective in the domains of wavelength and pola-rization and in the three spatial domains, so as to provide orthogonality in all five dimensions. Here we show true five-dimensional optical recording by exploiting the unique properties of the longitudinal surface plasmon resonance (SPR) of gold nanorods.
The longitudinal SPR exhibits an excellent wave-length and polarization sensitivity, whereas the distinct energy threshold required for the photo thermal recording mechanism provides the axial selectivity. The recordings were detected using longi-tudinal SPR-mediated two-photon luminescence, which we demonstrate to possess an enhanced wa-velength and angular selectivity comp-ared to conventional linear detection mechanisms. Combined with the high cross-section of two-photon luminescence, this enabled non-destructive, cross-talk-free readout. This technique can be immediately applied to optical patterning, encryption and data storage, where higher data densities are pursued.
II. CONVENTIONAL OPTICAL STORAGE SCHEMES
The conventional optical storage technologies are classified into three, depending on the number of dimensions that have been used for recording data. They are 2-Dimensional, 3-Dimensional and 4-dim-ensinal optical storage technologies. The 5-dimensio-nal DVD, discussing here utilizes five dimensions to store data. In spite of the conventional three dimen-sions it made use of two additional dimensions
III. TWO DIMENSIONAL OPTICAL STORAGE
In this technology the data is written in ‘pits’ on the surface of the disc. Examples are CD, DVD and blue ray disc. Smaller pits mean that for the same available area, more data can be stored. Moreover, the available data area for DVD disc is larger than the one of CD. This depends on how narrow is the laser beam used for recording as well as reading. That is how a DVD holds more than that of a CD and the storage capacity of a blue ray disc is very much higher than a DVD.
