Researchers in the Netherlands say they have come up with a way of using lasers to speed up magnetic hard drives -- and they expect to have a prototype by 2010.
A paper published by Daniel Stanciu of the Institute for Molecules and Materials at Radboud University Nijmegen describes a method of using ultrarapid pulses of polarised light to heat up areas on a hard disk and, crucially, using the same light to change the polarity of those areas. The polarity of the disk storage medium is reversed by reversing the polarity of the laser pulses, according to a report in Science.
Stanciu was not available for comment, but in the abstract accepted for publication by the Physical Review Letters, he wrote, "We experimentally demonstrate that the magnetisation can be reversed in a reproducible manner by a single 40-femtosecond circularly polarised laser pulse, without any applied magnetic field."
This optically induced, ultrafast magnetisation reversal, he said, was previously believed impossible, and it is the combined result of femtosecond laser heating of the magnetic system to just below the Curie point, and circularly polarised light simultaneously acting as a magnetic field.
Similar effects have previously been used in magneto-optical storage devices, but those used a magnetic field applied by conventional means, not by the laser.
According to Science, Stanciu expects to see a working prototype within a decade.
Matt Loney reported for ZDNet UK from London
