All-Solid-State Cryocooler Realized
ALBEQUERQUE, NM, Feb. 2, 2010 – The first-ever all-solid-state cryocooler, which allows coolers to reach temperatures so cold that they can only be obtained by liquefying gases, has been created for applications in airborne and spaceborne sensors.
The team, led by University of New Mexico professor, Dr. Mansoor Sheik-Bahae, under an Air Force Office of Scientific Research and multi-university grant, says that this discovery 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, compact, lightweight and agile," said Sheik-Bahae.
Under an AFOSR, MURI grant, the first-ever cryo cooler that can be applied to airborne and spaceborne sensors has been realized. (Image: Sheik-Bahae, University of New Mexico)
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.
In the future Sheik-Bahae and his team will continue collaborations with, Mauro Tonelli, professor at the University of Pisa in Italy, as well as with Dr. Richard Epstein of the Los Alamos National Lab. Together they plan to research product purity and new materials for cryocoolers.
"We are also pursuing optical pump sources that can further enhance cooling efficiency of the devices," he said.
For more information, visit: www.unm.edu
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