arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新，休息一下吧，周末愉快~~
arXiv 1802.05306physics.atom-ph
收藏

钠磁光阱激发态布居的模型无关测量

Model-independent measurements of the sodium magneto-optical trap's excited-state population

J. M. Kwolek, D. S. Goodman, S. A. Entner, J. E. Wells, F. A. Narducci, W. W. Smith

备注：
10 pages, 8 figures
发表信息：
Phys. Rev. A 97, 053420 (2018)
阅读 PDF
arXiv 页面 ↗HTML 原文 ↗

摘要：

利用由钠磁光阱和线性Paul阱组成的离子-中性混合阱，对钠磁光阱中原子的激发态态布居进行了与模型无关的测量。我们用光子激发了被困在MOT中的Na原子，并使用两种独立的方法来测量产生的离子：直接通过将它们捕获在我们的LPT中，间接通过监测MOT荧光的变化。通过这两种独立的方法测量电离率，我们有足够的信息直接确定MOT原子在激发态的布居。测量结果表明，在一定的激光强度范围内，MOT中原子的激发态布居符合标准的二能级模型强度依赖关系。然而，必须使用实验确定的有效饱和强度，而不是从二能级模型的理论预测值。我们测得I型Na MOT的有效饱和强度为$I_\mathrm{se}=22.9(3)\:\textrm{mW}/\textrm{cm}^2$，II型Na MOT的有效饱和强度为$I_\mathrm{se}=48.9(7)\;\textrm{mW}/\textrm{cm}^2$，分别约为理论估计值的1.7倍和3.6倍。最后，在大的陷阱激光强度，我们的实验揭示了一个明显的偏离两个能级模型在临界强度，我们认为是由于状态混合效应，其临界强度可以由一个简单的功率加宽模型确定。

英文摘要：

We present model-independent measurements of the excited-state population of atoms in a sodium (Na) magneto-optical trap (MOT) using a hybrid ion-neutral trap composed of a MOT and a linear Paul trap (LPT). We photoionize excited Na atoms trapped in the MOT and use two independent methods to measure the resulting ions: directly by trapping them in our LPT, and indirectly by monitoring changes in MOT fluorescence. By measuring the ionization rate via these two independent methods, we have enough information to directly determine the population of MOT atoms in the excited-state. The resulting measurement reveals that there is a range of trapping-laser intensities where the excited-state population of atoms in our MOT follows the standard two-level model intensity-dependence. However, an experimentally determined effective saturation intensity must be used instead of the theoretically predicted value from the two-level model. We measured the effective saturation intensity to be $I_\mathrm{se}=22.9(3)\:\textrm{mW}/\textrm{cm}^2$ for the type-I Na MOT and $I_\mathrm{se}=48.9(7)\;\textrm{mW}/\textrm{cm}^2$ for the type-II Na MOT, approximately 1.7 and 3.6 times the theoretical estimate, respectively. Lastly, at large trapping-laser intensities, our experiment reveals a clear departure from the two-level model at a critical intensity that we believe is due to a state-mixing effect, whose critical intensity can be determined by a simple power broadening model.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

↑