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题名	铷原子喷泉钟的新系统单元设计与部分误差评估
作者	邹凡
学位类别	硕士
答辩日期	2016
授予单位	中国科学院上海光学精密机械研究所
导师	魏荣
关键词	原子频标 铷原子喷泉钟 误差评估 微波综合器 二维磁光阱
其他题名	Sub-system construction and accuracy evaluation of rubidium atomic fountain clocks
中文摘要	本文介绍了本人在上海光机所（SIOM）量子光学实验室所做的85Rb喷泉钟单元系统搭建和在87Rb喷泉钟系统上所做的误差评估工作。 基于已有的87Rb喷泉钟的微波综合器，采用介质振荡器（DRO）与3GHz的梳状谱拍频，然后再与直接数字合成器（DDS）混频并将DRO锁定在85Rb喷泉钟Ramsey腔所需要的3.03573GHz的频率上，为85Rb喷泉钟提供了微波源。为了实现相位噪声的测试，采用自制的同轴陶瓷介质谐振器（MCRO）作为振荡器制作了另外两套链路。将采用DRO作为振荡器的链路与采用MCRO的链路进行比对，得到了微波综合器的相位噪声上限，测得的相位噪声在1Hz附近低于-90dBc/Hz。由于MCRO与DRO对噪声的贡献大小无法完全确定，进一步测量并区分各套链路的噪声仍在进行中。 为了提高喷泉钟的冷原子装载效率、减小死时间、降低Dick效应的影响，开展了二维磁光阱（2D-MOT）装载冷原子的研究。加工并装配了一套2D-MOT装置，2D-MOT与三维磁光阱（3D-MOT）通过差分管相连接，我们对该系统进行了抽真空和激活铷源等处理。另外，搭建了一套光学系统，为2D-MOT提供所需要的冷却光、探测光、再泵浦光、推射光。 在现有的87Rb喷泉钟系统的基础上，开展了部分误差评估工作。分析了自比对方法，对其进行了实验验证，并将其应用到冷原子碰撞频移和光频移的测量上。除此之外，还对微波相关的效应进行了理论分析，讨论了分布腔相移、微波透镜效应和微波泄漏对喷泉钟的影响。对喷泉钟的进一步评估和改善仍在进行中。
英文摘要	This thesis presents the tasks of sub-system construction of 85Rb atomic fountain clock (AFC) and part of the uncertainty evaluations of an 87Rb AFC. Based on the microwave synthesizer of the current running 87Rb AFC, dielectric resonator oscillator (DRO) is adopted to mix with a 3GHz frequency comb and then to mix with a direct digital synthesizer (DDS). The resulting signal is filtered and integrated by a feedback circuit which provides the error signal to lock the DRO to the required 3.03573 GHz frequency for 85Rb AFC. To measure the single side band phase noise (SSB-PN), two sets of home-made dielectric ceramic coaxial resonator oscillators (MCRO) are used as the voltage controlled oscillators to construct another two phase lock loops (PLL) to generate the required frequency. The two PLLs based on MCRO are compared with the PLL based on DRO and the results give the SSB-PN of both PLLs. The SSB-PN near 1Hz is less than -90dBc/Hz, which is the upper limit of the potential SSB-PN of DRO PLL. Since the exact values of SSB-PN of each PLL remain unknown, more research works are essential to extract the noise of DRO PLL from the comparison. To accelerate the loading rate of cold atoms in magneto-optical trap (MOT), diminish the dead time in AFC and reduce the Dick effet, the method of loading cold atoms from a two-dimensional MOT (2D-MOT) is analyzed. A 2D-MOT physical system, which is connected to a three-dimensional MOT, is made, degassed and activated. Moreover, the corresponding optical system is also constructed to provide the required cooling laser, probing laser, repumping laser and pushing laser. On the basis of the current running 87Rb AFC, the frequency shifts and uncertainties of several effects are evaluated. During the measurements, the self-comparison method is applied to the cold collisional frequency shift and light shift. Besides, the microwave related effects, including distributed cavity phase shift, microwave lensing effect and microwave leakage effect, are theoretically analyzed to help improving the evaluations of AFC. Evaluations of other effects that are important to the AFC are still ongoing.
语种	中文
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/16979]
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	邹凡. 铷原子喷泉钟的新系统单元设计与部分误差评估[D]. 中国科学院上海光学精密机械研究所. 2016.

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