A simple model is developed to study the laser cooling of solids. The condition of laser cooling of a solid is developed. By using some parameters of the Yb<sup>3+</sup> ion, which is most widely used in laser cooling, we then calculate the cooling power and the cooling efficiency. In order to make a more precise analysis, the effect of fluorescent reabsorption, which is unavoidable in the cooling process, is discussed using the random walk model. Taking Tm<sup>3+</sup> ion as an example, we derive the average number of absorption events and determine the change in quantum efficiency due to reabsorption. Finally, we obtain the red-shift of the fluorescent wavelength and the requirement of sample dimension.
© 2012 Chinese Optics Letters
Lasers and Laser Optics
Youhua Jia, Biao Zhong, and Jianping Yin, "Mechanism of refrigeration cycle on laser cooling of solids," Chin. Opt. Lett. 10, 031401- (2012)