US scientists build first 'antilaser'

The laser - a 50-year-old invention now used in everything from CDs to laser pointers - has met its match in the "antilaser," the first device capable of trapping and canceling out laser beams.

While such a device would seem most fitting in a science fiction movie, its real-world application will likely be in next-generation, optical computers, which will be powered by light in addition to electrons, U.S. researchers said on Thursday.

"It's a device which basically works like running a laser backwards," A. Douglas Stone of Yale University, who published his findings in the journal Science, said in a telephone interview.

While a laser takes in electrical energy and emits light in a very narrow frequency range, Stone said, his antilaser takes in laser light and transforms it into heat energy.

But it could be easily converted into electrical energy, he said.

Conventional lasers, which were invented in 1960, use a so-called "gain medium," such as a semiconductor material, to produce a focused beam of light waves.

Stone's device uses silicon as an absorbent "loss-medium" that traps light waves, which bounce around until they are converted into heat.

And while the technology seems cool, his antilaser would never be used as a potential laser shield.

"This is something that absorbs lasers. If a ray gun was intended to kill you, it's going to kill you," Stone said.

He said the most obvious use of his device is in computing. "The next generation of high performance computers are going to have hybrid chips," Stone said.

Instead of having chips with transistors and silicon, these new computers will use both light and electrical energy.

Stone said the device could be used as a sort of optical switch that can be turned on and off at will.

Ultimately, he said, the technology could find its way in radiology.

(Editing by Mohammad Zargham)