共查询到18条相似文献,搜索用时 109 毫秒
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研究了用于锶原子光晶格光钟原子冷却的塞曼减速器,应用增添补偿线圈的方法可以延长减速器的有效减速距离和增大减速器末端的磁场梯度,进而增加一级冷却俘获锶原子的数目,理论分析采用该方法实现的塞曼减速器较使用单一线圈塞曼减速器可以增加31.17%的俘获原子数目;飞行时间法测量了减速前后原子束中原子的速度分布,原子的最可几速度由380m/s降为43m/s,分布线宽相应变窄。荧光法测量俘获原子数目表明在相同实验条件下,应用补偿线圈后磁光阱俘获原子数目从1.26×106提高到1.81×106,增加30.4%。 相似文献
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87Sr原子存在核自旋,在磁场作用下原子能级会分裂成不同塞曼子能级.通过光抽运对原子进行自旋极化,其自旋极化谱线的探测为锶光钟系统的闭环锁定提供精确的频率参考.本文对~(87)Sr原子钟跃迁能级5s~2~1S_0→5s5p~3P_0中的m_F=+9/2和m_F=-9/2的塞曼磁子能级自旋极化谱线进行了探测.经过一级宽带冷却和二级窄线宽冷却与俘获后,锶冷原子温度为3.9μK,原子数目为3.5×10~6.利用邻近"魔术波长"的813.426 nm半导体激光光源实现水平方向的一维光晶格装载.采用归一化探测方法用线宽为Hz量级的698 nm钟激光对~1S_0→~3P_0偶极禁戒跃迁进行探测,在150 ms的探测时间下获得线宽为6.7 Hz的钟跃迁简并谱.在磁光阱竖直方向施加一个300 mGs的偏置磁场获得塞曼分裂谱,并通过689 nm的圆偏振自旋极化光进行光抽运,最终在探测时间为150 ms时,获得左右旋极化谱线线宽分别为6.2 Hz和6.8 Hz. 相似文献
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在精密测量领域中,高效地制备冷原子团具有重要的意义.在光晶格钟里,缩短冷原子团的制备时间可以降低Dick噪声,从而提高光晶格钟的稳定性.本文采用二维磁光阱加推送光的构型提高了三维磁光阱在超高真空环境中的装载率,并通过压缩磁光阱技术降低了原子团温度,实现了用于199Hg光晶格钟的增强型冷原子团制备.实验上通过优化三维和二维磁光阱的失谐量和磁场梯度以及推送光的失谐量和功率等参数,将三维磁光阱的199Hg冷原子装载率增强了51倍,提升至3.1×105 s–1,然后使用压缩磁光阱技术将199Hg冷原子团的温度降低至45μK,低于多普勒冷却理论温度.这种基于二维磁光阱的增强型冷原子团制备可在超真空环境下实现对三维磁光阱装载率的高增益,有效地缩短了冷原子团的制备时间,同时也降低了原子团的温度,有利于提高光晶格的转移效率,为其他冷原子实验中冷汞原子团制备提供了有效方案. 相似文献
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《光学学报》2020,(9)
主要介绍了可移动锶原子光晶格钟的系统研制和钟跃迁谱线探测。光钟系统采用尺寸为120 cm×50 cm×60 cm的小型化物理系统,通过光纤将模块化的子光路系统与物理系统连接。经过一级461 nm激光和二级689 nm激光冷却后,得到原子数目为1.02×10~6、原子温度为5.45μK的冷原子团。利用具有"魔术波长"的晶格光实现~(87)Sr的一维光晶格装载,晶格寿命为434 ms,晶格中原子温度为4.63μK。在具有超窄线宽的698 nm钟激光探测下,得到边带可分辨的钟跃迁谱、窄线宽简并谱、自旋极化谱及拉比振荡曲线。经钟激光探询后,得到的自旋极化谱的谱线线宽为11.79 Hz,接近傅里叶探测极限的理论值,为可移动光钟的闭环工作提供了频率参考。 相似文献
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量子投影噪声是影响光晶格钟的一个重要参数,提高磁光阱中装载率有利于降低量子投影噪声,可提升光晶格钟的性能.针对实验所用的汞原子单腔磁光阱,本文分析并计算了磁光阱中汞原子受力情况和一维运动规律,在此基础上用随机数方法对磁光阱中汞原子三维装载进行了数值计算,获得了磁光阱中的稳态原子数,研究了磁光阱的冷却激光的光强、失谐量以及磁场梯度等参数对稳态原子数的影响,得出了获得最优装载率的实验参数.涉及的计算方法和结论对汞原子光晶格钟的实验设计具有参考价值. 相似文献
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为实现锶原子光钟的空间应用,采用永磁体塞曼减速器,可有效规避塔状线圈造成的高功耗和体积占比大的问题,利于光钟的空间化发展。基于永磁体构建锶光钟的环状和柱状塞曼减速器,在减速原理、磁场构建和样品研制方面各有优劣,利用多普勒测速法可对两种减速器的减速效率进行测量,可将两种减速器的减速分布曲线累计分布后对比。实验结果表明:两种永磁体塞曼减速器都达到一定减速效果,但环状永磁体塞曼减速器在体积和减速效果上,相较单x方向的柱状永磁体塞曼减速器,体积减少了60%,重量减少了80%,减速效果部分区域效率高一倍,因此优势更为显著。进一步采用环状永磁体塞曼减速器俘获锶原子的三种同位素,完成了小型化锶原子光钟的一级俘获,满足零功耗、体积小的紧凑化光钟设计需求。 相似文献
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The magnetic field effect of a8S7/2-z6P7/2 lines of 151Eu and 153Eu in magnetic fields up to 66.7 mT has been studied by using laser atomic beam spectroscopy. The Zeeman level structures of the europium a8S7/2 and z6P7/2 states in magnetic fields were discussed. The location and intensity of the measured Zeeman transition lines were found in good agreement with the theoretical results. 相似文献
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光晶格中性原子光钟的不确定度已达到10-18量级. 本文介绍了碱土金属锶原子玻色子88Sr在“魔术”波长处的一维光晶格装载, 实现冷锶原子的囚禁并使锶原子的钟跃迁能级(5s2) 1S0-(5s5p) 3P0在此波长处的交流斯塔克光频移一致. 实验中半导体激光器产生“魔术”光波长(813 nm), 通过实验搭建光学驻波场并获得晶格激光聚焦光束, 束腰半径为38 μm. 经过一级冷却和二级冷却后温度约为2 μK的冷锶原子被此“魔术”波长光晶格囚禁. 通过实验测量得到锶原子玻色子88Sr光晶格寿命为270 ms, 数目约为1.2×105, 温度在3.5 μK左右, 此外研究了晶格光功率对晶格囚禁原子数目及温度的影响作用. 原子的光晶格装载为后续的钟跃迁提供了长的探测时间, 为进一步的光钟闭环提供了实验基础. 相似文献
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This paper reports the first time achievement of laser photolysis of thallium dimers by single photon absorption of N2-laser light at 337.1 nm resulting in a large population inversion of thallium 7 2S
excited state with respect to 6 2P
state. The photodissociation nitrogen laser pulse is spatially and temporally overlapped with the tunable dye laser pulse that is used for confirming the production of selectively excited thallium atoms. The dye laser excites the thallium atoms from 7 2S
state to high lying Rydberg states that collisionally ionize giving an ion-current signal which is subsequently processed by a box-car average/integrator and recorded on the chart recorder. The photodissociation of Tl2 to Tl(7 2S
) state demonstrates the existence of the molecular dissociative state 1g that is correlated with Tl 7 2S
+6 2P
states. A complete absence of 6 2P
state population among the photolysis products indicates a 100% prompt population inversion between 7 2S
and 6 2P
atomic states. 相似文献
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采用高温固相法在1300℃的温度获得了一种新型电子俘获型光存储材料 Sr2SnO4:Sb3+. 结果表明: 208 nm (Sb3+ 的1S0→1P1)和265 nm (1S0→3P1)的紫外光是Sr2SnO4:Sb3+ 的最有效信息写入光源; 其发射是覆盖400---700 nm的宽带(3P0,1→XXS0), 肉眼可看到淡黄色白光, 色坐标为(0.341, 0.395). 热释光谱研究结果表明: Sr2SnO4:Sb3+ 有分别位于39℃, 124℃, 193℃和310℃的四个热释峰. 其中, 39~℃的热释峰强度很低, 因而Sr2SnO4:Sb3+ 只具有不到140 s的微弱余辉. 而310℃的高温热释峰在空置1天后, 仍能保持约45.6%的初始强度, 并对980 nm的红外光有很好的红外上转换光激励响应. 因此, Sr2SnO4:Sb3+ 是一种具有一定的信息存储应用潜力的新型光存储发光材料. 相似文献
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Observation of photon recoil effects in single-beam absorption spectroscopy with an ultracold strontium gas 下载免费PDF全文
We report on observing photon recoil effects in the absorption of a single monochromatic light at 689 nm through an ultracold 88Sr gas,where the recoil frequency is comparable to natural linewidth of the narrow-line transition 5s2 1S0-5s5p 3P1 in strontium.In the regime of high-saturation,the absorption profile becomes asymmetric due to the photon-recoil shift,which is of the same order as the natural linewidth.The lineshape is described by an extension of the optical Bloch equations including the momentum transfers to atoms during emission and absorption of photons.Our work reveals the photon recoil effects in a simplest single-beam absorption setting,which is of significant relevance to other applications such as saturation spectroscopy,Ramsey interferometry,and absorption imaging. 相似文献
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THE 82S1/2→62D EXCITATION TRANSFER OF RUBIDIUM ATOMS INDUCED BY COLLISIONS WITH GROUND-STATE RUBIDIUM AND HYDROGEN MOLECULES 下载免费PDF全文
The processes of excitation transfer from the 82S1/2 state to the 62D state of rubidium in Rb(82S1/2)-Rb(52S1/2) and Rb(82S1/2)-H2 collisions have been studied experimentally. During irradiating the Rb vapor, mixed with H2, by two light beams for selective stepwise excitation, the Rb 82S1/2→52P3/2 direct fluorescence and the Rb 62D3/2→52P1/2 sensitized fluorescence have been measured as a function of H2 gas pressure. The measurements yielded the cross-sections σ(82S1/2→62D) and σ*(82S1/2→62D) of Rb 82S1/2→62D excitation tranfer induced by collisions with 52S1/2 atom and H2 molecules respectively. The results are discussed in detail. 相似文献
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We have deduced analytical solutions of an energy level diagram of the doubly driven/dressed atom for a two-level atom exposed to a strong near-resonant bichromatic laser field in a special case, i.e., the bichromatic field with frequencies ω1 and ω2, and Rabi frequencies ?1 and ?2, in which the first coupling field of ?1 acts on the bare atomic levels, and then the resulting singly dressed states are driven by the second coupling field of ?2, thus resulting in the doubly dressed atom.We have measured the probe absorption spectra of a doubly driven two-level atom. The system consists of 52S1/2, F= 2 and 5~2P_(3/2), F'= 3 states of ~(87)Rb atoms in a magneto-optical trap(MOT) as well as the cooling/trapping beams and an additional coupling field. As for the spectroscopic properties of the doubly driven two-level atom, theoretical analytical solutions are in general agreement with the experimental spectrum as a whole. 相似文献