Optical refrigeration expected to enhance airborne and spaceborne applications

By | January 29, 2010

Under an Air Force Office of Scientific Research, multi-university grant, a team led by University of New Mexico professor, Dr. Mansoor Sheik-Bahae created the first-ever all-solid-state cryocooler that can be applied to airborne and spaceborne sensors.

This technology, which allows coolers to reach temperatures so cold that they can only be obtained by liquefying gases, may lead to advances in superconducting electronics because it would enable miniaturization for cooling purposes.

Graduate students Denis Seletskiy and Seth Melgaard designed and performed the experiments at UNM’s department of Physics and Astronomy in collaboration with researchers from Los Alamos National Laboratory and the University of Pisa, Italy.

“Optical refrigeration or solid state optical refrigeration technology offers many advantages over currently used, bulky mechanical coolers because it is vibration free (no moving parts), compact, lightweight and agile (fast turn-on and off),” said Sheik-Bahae.

Previously, only solid-state coolers based on standard thermoelectric devices were able to reach temperatures as low as 170K, and even so, only with minimal efficiency.

“We obtained cooling down to 155K using optical refrigeration,”said Sheik-Bahae. “We expect that material research may lead to temperatures dipping below 77K (boiling point of liquid nitrogen) and in the future as low as 10K may be possible,” he added.

In order to achieve their results, the scientists enhanced cooling efficiency by exploiting resonances in the absorption spectrum, growing pure crystals, using thin optical fibers, keeping their sample in thermal isolation inside a vacuum and by trapping laser light in a resonant space. …

via Optical refrigeration expected to enhance airborne and spaceborne applications.


Byline: John Fleck Journal Staff Writer

* Keeping satellites from overheating a possible use for cold technology

When you fire a laser at something, you expect it to get hot, not cold.

In a nondescript lab building tucked in the shadow of University of New Mexico Hospital, Mansoor Sheik-Bahae is defying expectations.

UNM physics professor Sheik-Bahae is exploiting one of those loopholes that makes quantum mechanics endlessly puzzling, even to a hardened physicist.

In the lab, a narrow beam of green light bounces through a series of mirrors and a filtering system, creating the precise frequency used to make the quantum magic work.…

Laser Cools It in UNM Laboratory

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