How Do Anti-Lasers Work?

In my school days, I was taught about the lasers and their medical and industrial applications. Then later on I actually studied how do lasers work and what they literally mean by Light Amplification by Stimulated Emission of Radiation. Never ever, I thought that one day even reverse of this could happen, but it eventually did. Physicists of Yale University have come up with such a device that can do the laser process in a reverse way called anti-lasers.




Image Credit: PhysicsWorld

What do these anti-lasers actually do? They absorb the light striking them and convert it into thermal energy. This thing absorbs around 99% of the light incident upon it and converts it into thermal energy. However, the thing is that the anti-laser does not get triggered with just any light source but needs coherent light. Whenever a beam of coherent light is incident on this device, the incident beam is split into two parts. Both these beams are then made incident upon opposite sides of a polished silicon wafer to produce interference and thermal energy.

But it is not as easy as it sounds. The stake is that both the incident beams must have the same wavelength and amplitude. Only with a correct phase difference between the two beams, the material that would otherwise reflect would absorb almost all the incident light. So the time delays between the beams are to be taken care of. The correct wavelength of the light is determined by the physical properties of the material used. For the prototype they have made, the suitable wavelength lies in the infrared region. Still, material matching the light from visible range can be synthesized. A proper addendum to this device can also make the anti-laser give an electrical output (maybe a thermocouple or so). In this fashion, the light is entrapped in the device and hardly 1% of it can escape.

I appreciate this invention however I doubt the scope of its applications. As one of my friends has said it earlier in a post, #-Link-Snipped-#. Apart from acting as a detector for a particular region of light I could not find any other applications. The fact that it can absorb light only from a certain region can not make it a substitute for solar cells. Let us hope for some more advancement in this field to make this invention more useful.