When the first laser was built in 1960, everyone agreed that it was pretty impressive, but no one quite knew what to do with it. It was famously called a “solution in search of a problem.”
Today, lasers are used for eye surgery, CD players, checkout scanners and Pink Floyd stage shows. Farmers even use them to level fields.
Now, 51 years later, Yale University researchers have built the world’s first anti-laser. Exactly what you can do with it remains to be seen, although radiology and computers are among the possibilities.
A. Douglas Stone, a physicist, and his team described the anti-laser in Friday’s issue of Science.
As its rather sci-fi nickname suggests, the anti-laser does the exact opposite of a laser. Instead of emitting a beam, it absorbs the light with the same precision. The device’s technical name is “coherent perfect absorber.”
The possibility of an anti-laser had been suggested by other scientists, but only in passing, Stone said. And other physicists have stumbled upon the basic premise while working on other projects, he said, but they did not follow through.
“Nobody took it serious, until us,” Stone said. “It was literally a footnote.”
The anti-laser is set up to split a single laser beam into two and direct the two beams to head toward each other, meeting at the paper-thin silicon wafer. The light’s waves are precisely tuned to interlock with each other and become trapped. They then dissipate into heat.
Now that the anti-laser has been built, what exactly do you do with it? Cao also has suggested that it could be useful in radiology, capturing images of human tissue normally too deep to see.