大积分球冷却原子的实验研究及积分球冷原子钟系统优化
文献类型：学位论文
| 作者 | 郑本昌 |
| 学位类别 | 博士 |
| 答辩日期 | 2014 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 刘亮 |
| 关键词 | 激光冷却 大尺寸积分球 积分球冷原子钟 法拉第旋光效应 Ramsey条纹 |
| 其他题名 | Study of Laser Cooling in Large-scale Integrating Sphere and Opitimization of Integrating Sphere Cold Atom Clock |
| 中文摘要 | 本论文介绍了作者在积分球冷却原子和积分球冷原子钟方面的工作，主要内容分为两个部分：大积分球冷却87Rb原子实验和积分球冷原子钟关键技术研究。 论文的第一章是引言，第二章介绍了激光冷却与陷俘的内容，包括发展历史，理论基础，典型的激光冷却与陷俘机制分析与方法。第三章介绍了频标的发展历史与技术基础，包括获得Ramsey条纹的方法，闭环系统的工作原理及频标性能的评估指标。 第四章介绍作者在大尺寸积分球冷却87Rb原子中的工作。我们利用一个直径为100 mm的积分球，获得了数量为2E10的冷原子，比我们之前45 mm直径的积分球获得的冷原子数高了一个数量级。在现有的激光器和光路条件下，我们研究了大尺寸积分球冷却的各项关键参数，研究结果证明大积分球可以制备实验所需的更多冷原子。因此，大积分球是一个很好的产生超大数量冷原子源的方法，这样一个大尺寸的冷原子源对于研究冷原子与激光相互作用提供了一个很好的介质源。 第五章介绍了作者对积分球冷原子钟系统进行的优化。积分球冷却在建立小型化冷原子钟方面有很大潜力，我们小组搭建了国内第一台积分球冷原子钟的实验平台。在积分球冷原子钟实验里，我们介绍了系统的基本情况，然后针对初期实验结果对原子钟系统进行了优化。首先，我们利用脉冲冷却原理，优化实验时序压缩了原子钟运行周期，将循环周期时间压缩了一个数量级以上，这项工作能够有效提高积分球原子钟的的性能；其次，我们优化了温控系统和探测系统，减小了探测系统噪声。最终我们获得了信噪比约为150，线宽约为44 Hz的Ramsey干涉条纹，并实现了积分球原子钟的闭环锁定，短期稳定度达到E-12。 第六章介绍了积分球冷原子里的法拉第旋光效应。基于这种效应我们用正交偏振探测方法代替吸收探测法，这种方法具有高灵敏度与高对比度的特点，并首次将这种方法应用于积分球冷原子钟钟信号的探测上，获得了对比度大于90%的Ramsey干涉条纹。 |
| 英文摘要 | This thesis presents my work on the laser cooling of rubidium atoms and integrating sphere cold atom clock. The main content of this thesis is divided into two parts: laser cooling of rubidium atoms in a large-scale integrating sphere and optimization of the experimental process in integrating sphere cold atomic clock. Introduction is presented in chapter 1. The history, basic theory and typical mechanism of laser cooling and trapping atoms are discussed in chapter 2. In chapter 3, we introduce the history and technological base of frequency standard. Cooling of Rb87 atom in a large-scale integrating sphere is presented in chapter 4. Approximately 2E10cold atoms are captured in a large-scale integrating sphere with the diameter of 100 mm, the number of cold atoms is one order more than the previous one with the diameter of 45 mm. Under the present experimental conditions, factors affecting the number of cold atoms are analyzed. Results show that increasing the size of integrating sphere can cool more atoms. Thus, laser cooling of atoms in a large-scale integrating sphere is a good way to produce massive number of cold atoms, which provide a valuable source for the study of interaction between cold atoms and laser field. Optimization of integrating sphere cold atom clock is presented in chapter 5. The characters of laser cooling atoms based on integrating sphere make it potential in building compact cold atom clock. Our group build the first domestic integrating shere cold atom clock. In this thesis, the experimental setup is introduced along with the preliminary result, and then the optimization of the experimental process is presented, especially in the shortening of the time of clock cycle. We confirm that the time of clock cycle can be reduced one order than before, which would be useful to improve the performance of the integrating sphere cold atom clock. Then the temperature control and probe system are optimized to reduce the probe noise. At last, 44 Hz Ramsey fringe is achieved with SNR of 150. The preliminary lock of integrating cold atom clock is acquired with a short time stability E-12. In chapter 6, the Faraday rotation effect in integrating sphere is observed and the orthogonal polarization detection based on this effect is used in the detection of integrating shere cold atomic clock signal. By using this detection method, we obtain a ramsey fringe with 92% contrast, which is higher than that of using absorption detection. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15872]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 郑本昌. 大积分球冷却原子的实验研究及积分球冷原子钟系统优化[D]. 中国科学院上海光学精密机械研究所. 2014. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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