Dielectric mirror leakage at large angles of incidence limits the effectiveness of solid state optical refrigerators due to reheating caused by photon absorption in an attached load. In this paper, we present several thermally conductive link solutions to greatly reduce the net photon absorption. The Los Alamos Solid State Optical Refrigerator (LASSOR) has demonstrated cooling of a Yb/sup 3+/ doped ZBLANP glass to 208 K. We have designed optically isolating thermal link geometries capable of extending cooling to a typical heat load with minimal absorptive reheating, and we have tested the optical performance of these designs. A surrogate source operating at 625 nm was used to mimic the angular distribution of light from the LASSOR cooling element. While total link performance is dependent on additional factors, we have found that the best thermal link reduced the net transmission of photons to 0.04%, which includes the trapping mirrors 8.1% transmission. Our measurements of the optical performance of the various link geometries are supported by computer simulations of the designs using Code V, a commercially available optical modeling software package.
© 2008 International Society of Optical Engineering (SPIE)
Parker, J., D. Mar, S. Von der Porten, J. Hankinson, K. Byram, C. Lee, K. Mayeda, R. Haskell, Q. Yang, S. Greenfield, and R. Epstein. "Designs and optical tests of thermal links for an optical refrigerator." Proceedings from the Laser Refrigeration of Solids SPIE Conference in San Jose California on 23 January 2008. (2008): 69070D.1-69070D.12. DOI: 10.1117/12.764166