World's First Anti-Laser Built
Two scientists Hui Cao and A. Douglas Stone at Yale University have built the laser’s first doppelganger: the anti-laser. While a conventional laser emits a constant beam of light in one direction, the anti-laser simply does the opposite. It takes that same steady light stream and interacts with it in such a way that it absorbs and cancels out the light. And scientists hope the strange creation could help the fight against cancer.
Yale physicist A. Douglas Stone, a coauthor of the paper, first suggested the antilaser in a theoretical paper last July. Stone and colleagues had noticed that several other researchers had hinted at the idea of a laser that runs backward, and some problems in engineering called for a way to completely snuff out light. But no one had ever put the two ideas together.
“Others discovered independently that there’s an optimal condition where they can have the best absorption,” Cao said. “But they didn’t realize this was a time-reversed laser. They didn’t know they can get in principle perfect absorption.”
