Increasing data storage capacity

USING OPTICAL media made from common products, researchers at Boston College's Eugene F. Merkert Chemistry Centre have discovered a new way to store nearly 20 times more data on disc than can be currently stored on a standard DVD.

Their report, published in Nature Materials, describes new fluorescent materials that are stable, inexpensive and able to store 3D data at high densities.

The findings have implications for the storage capacity of computers ranging from massive reference-storage units to desktop PCs.

The storage media created by Boston College Chemistry Professor John Fourkas and colleagues work by using laser light to `write' a fluorescent spot at specific locations in the material.

The data are written into the material by a process known as multiphoton absorption, and can be efficiently read out at relatively low laser intensities.

Previous materials used for multiphoton data storage either require costly laser systems or degrade when the data is read out — making them unstable for long-term data storage.

The new fluorescent materials can be scanned repeatedly to read out the information — with little degradation seen after a million read cycles.

The storage density of these fluorescent media is an order of magnitude higher than a DVD, and the materials are surprisingly versatile, says Fourkas.

They can take a number of different forms, such as molecular glasses or crosslinked polymers, and can be moulded into any shape or chemically modified to improve their properties. In future, hard disk drives may no longer need to be disk-shaped.

The genesis of the research can be traced back several years, when Fourkas' co-authors — Christopher Olson and Michael Previteat the Massachusetts Institute of Technology — saw that some materials fluoresced when hit by a laser beam.