Japanese and Dutch researchers have succeeded in changing the magnetic polarity of a memory bit using circularly-polarized laser light instead of an applied magnetic field. The process is about 50,000 times faster than magnetic switching and could eventually lead to ultra-fast all-optical magnetic hard disk drives. Theo Rasing of the Radboud University Nijmegen and colleagues at Nihon University, Japan, demonstrated their method by flipping the magnetization of a 5 micrometer-wide spot on a thin magnetic film from up to down and vice versa. 5 micrometers is much wider than the bits on a modern hard drive, however, so there is still much development work to be carried out before laser-driven hard drives are a reality.
Illuminated hard drives