Slashdot Mirror
Scientists Invent World's First Anti-Laser
Velcroman1 writes "Two scientists 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. A. Douglas Stone, one of the two researchers behind the project, said he came up with the idea for a 'nega-laser' when working with equations for a random laser with his partner in crime, Hui Cao. 'I figured, if we just somehow illuminated the cavity, and replaced the gain medium with something that tends to absorb light, we could essentially reverse the process,' Stone said. Oh, that makes sense."
Now they'll create freaking anti-sharks to attach these to.
All they really needed to say was that it's the time-reversed counterpart of a laser. Calling it an "anti-laser" makes it sound like it shoots out a beam of darkness or something like that (which could be cool, but physically impossible).
Why this is neat is that, because it's the reverse of a laser, it'll absorb some frequencies almost perfectly while ignoring others. The reason why they said this would work for cancer, for instance, is that you could embed some of these dudes in the cancer (there's techniques for that, I have no idea how they work) and then bombard them with a laser frequency that normally passes harmlessly through humans. Areas without these reverse-lasers will be unaffected, but areas with them will get really hot, killing the cancer. We use similar techniques already (with I think gold, I'm not quite sure) in order to localize radiotherapy, but I believe that the radiation used in the current methods still kills a lot of normal cells on its own.
The article is absolute shit, but if you ignore everything the journalist wrote and just read what the physicist said you can get an idea of how this works.
Basically, it's the reverse of a laser; the physicist meant "anti-laser" as in "anti-matter" (because if you reverse the flow of time, anti-matter looks like regular matter).
Normal lasers take power in and emit light at a specific frequency; this thing takes light in at a specific frequency and emits power. In other words, if you take a video of a laser and play it backwards, that's this thing.