Scientists create new 'anti-laser' device

Posted Feb 20, 2011 by Kimberley Pollock
Invented over 50 years ago the laser has long been a hero of both science fiction and the real world. Now scientists at Yale University have invented its antithesis, the anti-laser, capable of trapping and cancelling laser beams.
In the anti-laser  incoming light waves are trapped in a cavity where they bounce back and forth unt...
In the anti-laser, incoming light waves are trapped in a cavity where they bounce back and forth until they are eventually absorbed. Their energy is dissipated as heat.
Photo courtesy of Yale / Yidong Chong
In simple terms the anti-laser works by interfering with incoming beams of light in such a way as to perfectly cancel each other out. "It's a device which basically works like running a laser backwards," said Yale Professor A Douglas Stone, reported the ABC.
Yale describe the process as:
The team focused two laser beams with a specific frequency into a cavity containing a silicon wafer that acted as a ‘loss medium.’ The wafer aligned the light waves in such a way that they became perfectly trapped, bouncing back and forth indefinitely until they were eventually absorbed and transformed into heat.
The official term for the device is a “coherent perfect absorber” (CPA) and the research is explained in detail in the 18 February issue of the journal Science.
Any new form of laser is bound to light up the minds of science fiction fans but unfortunately the anti-laser does not have the potential to become the ultimate laser shield. "This is something that absorbs lasers. If a ray gun was intended to kill you, it's going to kill you," Professor Stone said in the ABC report.
According to Yale the new anti-laser will have a wide range of applications in everything from optical computing to radiology. The computing world is particularly abuzz with the ant-laser and PC World reports that the research could be “an integral element in optical computers, a long promised successor to today's computers”.
Yale reports that the next stage of the research is to develop more sophisticated CPAs in order to improve absorption from 99.4 percent of all light received to the theoretically possible 99.999 percent. Simulations have also shown that the current one centimeter wide CPA can be shrunk to a compact six microns.