Modelling thermal parasitic load lines for an optical refrigerator

[摘要] Optical refrigeration is currently the only completely solid state cooling method capable of reaching cryogenic temperatures from room temperature. Optical cooling utilizing Yb:YLF as the refrigerant crystal has resulted in temperatures lower than 123K measured via a fluorescence thermometry technique. However, to be useful as a refrigerator this cooling crystal must be attached to a sensor or other payload. The phenomenology behind laser cooling, known as anti-Stokes fluorescence, has a relatively low efficiency which makes the system level optimization and limitation of parasitic losses imperative. We propose and model a variety of potential designs for a final optical refrigerator, enclosure and thermal link; calculate conductive and radiative losses, and estimate direct fluorescence reabsorption. We generate parasitic load-lines; these curves define temperature-dependent minimum heat lift thresholds that must be achieved to generate cooling for detectors.

[发布机构] Applied Technology Associ., 1300 Britt St. SE, Albuquerque; NM; 87123-3353, United States^1;Rensselaer Polytechnic Institute, 110 8th St., Troy; NY; 12180, United States^2;Spacecraft Component Thermal Research Group at Air Force Research Labs Kirtland, AFB, NM; 87117-5776, United States^3

[效力级别] 物理学 [学科分类] 材料科学（综合）

[关键词] Anti-Stokes fluorescence;Cryogenic temperatures;Fluorescence reabsorption;Fluorescence thermometry;Optical refrigeration;Solid-state cooling;System level optimization;Temperature dependent