Wednesday, September 14, 2005

Light has been stopped in its tracks for more than one second, setting a new record over a thousand times longer than the previous one.

Researchers at the Australian National University used a technique called electromagnetically induced transparency in which a beam of laser light puts the atoms in a solid sample into a state in which a signal light pulse can be trapped.

Most previous stopped-light demonstrations have used gases rather than solid materials. Light had previously been stopped in a solid (yttrium–silicate doped with atoms of praseodymium), but only for a few milliseconds.

Although the efficiency of the storage was low in this experiment, the researchers believe they can improve the efficiency by using a thicker sample and by increasing the concentration of praseodymium in the sample. The technique could be useful in quantum information processing applications such as quantum computers.