In a first-of-its-kind research, University of Washington scientists have managed to use laser beams to refrigerate water under real-world conditions.
Since its invention, lasers have always been used as heating implements; the concentrated beams of light have never been used to cool down materials. But, now, the researchers claim to have discovered a new method of refrigerating liquid using an infrared laser.
"Typically, when you go to the movies and see Star Wars laser blasters, they heat things up," said senior author Peter Pauzauskie, UW assistant professor of materials science and engineering in a statement, reported Dailymail.
"This is the first example of a laser beam that will refrigerate liquids like water under everyday conditions. It was really an open question as to whether this could be done because normally water warms when illuminated."
During the research, the scientists succeeded in using an infrared laser to drop the temperature of water by around 2°C (36°F). In order to achieve this phenomenon, they used a material commonly found in commercial lasers but made the laser process run in reverse. They used the infrared laser light to illuminate a single microscopic crystal floating in the water, causing a glow that has slightly higher energy as compared to the light absorbed by the particle. This higher-energy glow directs heat away from the crystal and the surrounding water, effectively refrigerating the material, reported TechTimes.
According to the researchers, the breakthrough discovery may be used by industrial users to "point cool" small areas with a focused point of light. For example, microprocessors might someday use laser beams to cool specific parts in computer chips to prevent overheating and enable more efficient information processing.
"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," Pauzauskie added.
"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."
The study has been published in the journal Proceedings of the National Academy of Sciences.
