100 times faster hard drives using laser to write data


laser.jpgCurrent hard drives which use magnets to write and read binary data are hitting a speed block and if computers are to become faster they will require a different and faster data transfer medium. Researchers at Radboud University Nijmegen in the Netherlands have used laser light to write data to a magnetic hard drive at very high speeds. The technique works because the photons transmitted by the laser actually carry angular momentum, allowing them to interact with the hard drive. Also, each laser pulse heats a tiny space on the disk just enough to make changing its polarity–thereby storing a bit of data–a little easier. The key is reversing the polarity of the laser pulses, which can produce the equivalent of either a 1 or a 0 of binary code on the disk storage medium.


The researchers have managed to transfer data at intervals of about 40 femtoseconds, or quadrillionths of a second, which is about 100 times faster than conventional magnetic transfers. One of the biggest drawback is that the footprint of the laser pulse on the disk is about 5 microns wide, which is considerably larger than the footprint produced by existing data-transfer systems. The next roadblock is to find a cheap laser technology that can fire pulses lasting less than 100 femtoseconds.