Berlin 2014 – scientific programme
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Q: Fachverband Quantenoptik und Photonik
Q 66: Ultracold atoms and molecules II
Q 66.6: Talk
Friday, March 21, 2014, 15:15–15:30, DO26 208
Thermodynamics and redistributional laser cooling in dense gaseous ensembles — •Katharina Knicker, Stavros Christopoulos, Peter Moroshkin, Anne Saß, Lars Weller, and Martin Weitz — Institut für Angewandte Physik der Universität Bonn
Laser cooling via collisional redistribution of fluorescence is a very efficient cooling technique applicable to ultradense gaseous ensembles. A high pressure environment ensures frequent collisions of optically active rubidium atoms with a noble buffer gas which shift the atomic resonances, allowing for absorption of a far red-detuned irradiated laser beam. Subsequent spontaneous decay occurs closer to the unperturbed resonances resulting in the extraction of kinetic energy of the order of kBT during each cooling cycle. The induced temperature changes are determined through thermal deflection spectroscopy and can be as high as 500K. Kennard-Stepanov analysis of the pressure-broadened absorption and fluorescence spectra allows for the determination of temperature changes in a non-interacting manner. Further investigations include redistributional cooling of molecular systems.