Scientists one step away from making freeze ray with ‘cool’ laser

17 Nov 2015

A team of scientists keen to change the way lasers have always worked has developed a laser that actually cools down the area it is being fired at, giving science-fiction fans hope an actual freeze ray could be on the way.

The freeze ray has always been one of the coolest (pun actually not intended in this case) weapons seen in science-fiction films, capable of freezing a foe and then, with a kick, breaking them down into millions of pieces.

But while this has always looked great, the science behind it has had to deal with the problem that lasers have until now always heated up an object it is pointed at due to the nature of light being focused on one area.

But now, a team of researchers from the University of Washington (UW) has confirmed a major breakthrough in photonics by, for the first time, creating a laser that actually cools its target area, offering a whole new range of scientific and everyday applications.

Publishing its findings in Proceedings of the National Academy of Sciences, the team developed an infrared laser that effectively reversed the typical laser process by illuminating a single microscopic crystal suspended in water with infrared laser light to excite a unique kind of glow that has slightly more energy than the amount of light absorbed.

UW cooling laser

The cooling laser developed at UW. Image via Dennis Wise/UW

In doing so, this glow sucks heat away from the target area, reducing its temperature to just 2ºC.

“Typically, when you go to the movies and see Star Wars laser blasters, they heat things up. This is the first example of a laser beam that will refrigerate liquids like water under everyday conditions,” said the senior author of the study, Peter Pauzauskie. “It was really an open question as to whether this could be done because normally water warms when illuminated.”

Such cool beam technology, the team said, could play into the eventual development of a laser to be included with microprocessors, which could target a beam at a particular area of the chip to prevent it from overheating.

It could also have biological uses, allowing medical researchers to slow down the rate at which a cell changes to study it in greater detail.

Not only has the team managed to achieve this, but it has also discovered a means of significantly reducing the cost of the manufacturing of laser crystals using a new hydrothermal process.

Of course, the technology is still very much in its early developmental stages and quite energy intensive, so enlarging it and making it more efficient are the next steps for the researchers.

“Few people have thought about how they could use this technology to solve problems because using lasers to refrigerate liquids hasn’t been possible before,” said Paden Roder, lead author of the study. “We are interested in the ideas other scientists or businesses might have for how this might impact their basic research or bottom line.”

Ice image via Shutterstock

Colm Gorey was a senior journalist with Silicon Republic