Ivanov Andrei, Rozhdestvensky Yuriy, Perlin Evgeniy
Appl Opt. 2016 Oct 1;55(28):7764-7770. doi: 10.1364/AO.55.007764.
In this paper, quantum mechanical calculations of cooling characteristics for the Yb: YLF system with use of the vibronic model of laser cooling are presented. Dynamics of the laser cooling process for the seven-level system of an Yb ion is described by the density-matrix formalism. Dependences of the cooling characteristics on the pump intensity are obtained for various temperatures and absorption coefficients of impurity ions. It is shown that the pump intensity, at which the net cooling power has a maximum, depends on temperature. Thus, choosing the intensities, which correspond to the net cooling power maximum over the entire temperature range, we achieve a lower sample temperature at a shorter time than in the case of using a constant intensity throughout the cooling process. Calculations are performed for the parameters of the Yb:YLF system.
本文介绍了利用激光冷却的电子振转模型对Yb:YLF系统冷却特性进行的量子力学计算。Yb离子七能级系统激光冷却过程的动力学由密度矩阵形式描述。针对杂质离子的不同温度和吸收系数，得出了冷却特性对泵浦强度的依赖关系。结果表明，净冷却功率达到最大值时的泵浦强度取决于温度。因此，选择在整个温度范围内对应净冷却功率最大值的强度，与在冷却过程中使用恒定强度的情况相比，我们能在更短时间内实现更低的样品温度。针对Yb:YLF系统的参数进行了计算。
