The world's first anti-laser

Physicists have built the world's first device that can cancel out a laser beam - a so-called anti-laser. The device, created by a team from Yale University, is capable of absorbing an incoming laser beam entirely.

But this is not intended as a defence against high-power laser weapons, the researchers said. Instead they think it could be used in next-generation supercomputers which will be built with components that use light rather than electrons.

Professor Douglas Stone and colleagues at Yale University had initially been developing a theory to explain which materials could be used as the basis of lasers.
Strange lasers. Recent advances in laser design have resulted in a number of unusual devices that do not fit the traditional concept of a laser, Professor Stone explained.

"So we were working on a theory that could predict what could be used to form a laser," he said.

That theory also predicted that instead of amplifying light into coherent pulses, as a laser does, it should be possible to create a device that absorbs laser light hitting it, said Professor Stone - an anti-laser. They have now succeeded in building one.