Lasers are normally used to burn or heat things, but now they are also able to cool the temperature of things like water, scientists at the University of Washington (UW) in Seattle say.
The first theories behind lasers were formulated by scientists in 1957. Three years later, in 1960, the first laser was built. Even since then, the devices were used to burn, cut, heat, and measure things, but never to refrigerate them. Lasers also captivated people’s imagination in Sci-Fi Movies.
Researchers at the University of Washington – who published their paper in the Proceedings of the National Academy of Sciences – were the first to ever use a laser to refrigerate water (and not in a vacuum).
Dr. Peter Pauzauskie, an assistant professor of materials science and engineering at the University of Washington said that this is the first laser beam to ever refrigerate liquids (in this case water) under regular weather conditions. Scientists wondered whether this could also be done in warmer weather, Dr. Pauzauskie added.
Although in 1995, scientists at the National Laboratory in Los Angeles used laser refrigeration, the process took place under vacuum conditions, and not under everyday weather conditions, such as the experiment of the UW researchers.
In their research, the scientist used a high-heat laser, which they aimed at a minuscule crystal that was suspended in water. The heat of the laser generated a glow that carried heath away from both the water and the crystal. To find out whether the crystal was indeed cooling and becoming refrigerated, scientists designed it beforehand to change colour as it cools.
According to scientists at the University of Washington, the process of laser refrigeration is quite energy-demanding, so they only applied it on a single nanocrystal – material particle composed of atoms, which is at least one dimension smaller than 100 nanometres. However, they want to improve the efficiency of the laser and continue their experiments.
Laser refrigeration could have applications in the real world, for instance to isolate molecules for research. The new discovery could also be used in biological research, to target small areas that need cooling.
Dr. Pauzauskie, a scientist at the U.S. Department of Energy’s Pacific Northwest National Laboratory in Richland, Wash, said that cell division, as well as the way in which enzymes and molecules function are things of great interest.
Previously, scientist did not have the right technology to refrigerate them to study their features, but the new laser-refrigeration technique may help with that.
Image Source: techtimes