Sounds like science fiction, right? It’s not. A team of researchers from the University of Washington have developed a laser that can cool water and other liquids under real-world conditions.
Developed in 1960, most of us have thought lasers and heat were synonymous with each other. When we all see The Force Awakens next month, we’re going to see a lot of lasers heating things up. But the team of researchers were able to use an infrared laser to cool water by nearly 36 degrees Fahrenheit.
Scientists were never sure if this was even possible, “because normally water warms when illuminated,” said senior author Peter Pauzauskie.
Why an infrared laser?
The researchers were thinking about biological applications. Visible light is a no-go because it can give cells sunburn.
Pauzauskie explains the possible perks of laser cooling in biology.
“There’s a lot of interest in how cells divide and how molecules and enzymes function, and it’s never been possible before to refrigerate them to study their properties,” said Pauzauskie. “Using laser cooling, it may be possible to prepare slow-motion movies of life in action. And the advantage is that you don’t have to cool the entire cell, which could kill it or change its behavior.”
How the laser cooling works?
They aimed their infrared laser at a single microscopic crystal suspended in water. This produces a unique glow that appears reddish-green and has a bit more energy than the amount of light absorbed. Heat from the crystal and surrounding water is carried away by the higher-energy glow.
Laser cooling isn’t a new concept. The process was first demonstrated at the Los Alamos National Laboratory in 1995. But that was in a vacuum. The UW team managed to get it the process working in liquids and real-world conditions.
As with all breakthroughs, these things are rarely cheap. The UW team did manage to cut costs in one area – creating the laser crystal. Using a low-cost hydrothermal process, the researchers show how to create a well-known laser crystal that can be built quickly and scale.
The biggest challenge to overcome is power. Right now, the laser cooling process uses lots of energy according to Pauzauskie. More work will need to be done to make the process more energy efficient.
“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,” Pauzauskie said. “We are interested in the ideas other scientists or businesses might have for how this might impact their basic research or bottom line.”
The potential applications are endless. From military hardware and consumer electronics to biology.
The study was recently published in the journal Proceedings of the National Academy of Sciences.