BBC NEWS: How to fit 300 DVDs on one disc

BBC NEWS | Science & Environment | How to fit 300 DVDs on one disc

A new optical recording method could pave the way for data discs with 300 times the storage capacity of standard DVDs, Nature journal reports.

The researchers say this could see a whopping 1.6 terabytes of information fit on a DVD-sized disc.

They describe their method as "five-dimensional" optical recording and say it could be commercialised.

The technique employs nanometre-scale particles of gold as a recording medium.

Researchers at Swinburne University of Technology in Australia have exploited the particular properties of these gold "nano-rods" by manipulating the light pointed at them.

The team members described what they did as adding two "dimensions" to the three spatial dimensions that discs already have.

They say they were able to introduce a spectral - or colour - dimension and a polarisation dimension.

The scientists used the nanoparticles to record information in a range of different colour wavelengths on the same physical disc location. This is a major improvement over traditional DVDs, which are recorded in a single colour wavelength with a laser.

Also, the amount of incoming laser light absorbed by the nanoparticles depends on its polarisation. This allowed the researchers to record different layers of information at different angles.

The researchers thus refer to the approach as 5-D recording. Previous research has demonstrated recording techniques based on colour or polarisation. But this is the first work that shows the integration of both. As a result, the scientists say they have achieved unprecedented data density.