冷原子微波频标的原理与发展  

Principle and Development of Microwave Frequency Standards of Cold Atoms

作　　者：魏荣[1,3] 李耀[1,2,3] 汪凌珂 吕德胜 Wei Rong;Li Yao;Wang Lingke;LüDesheng(Key Laboratory of Quantum Optics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;College of Materials Science and Opto-Electronic Technology,University of Chinese Academy of Sciences,Beijing 100049,China;Aerospace Laser Technology and System Department,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China)

机构地区：[1]中国科学院上海光学精密机械研究所量子光学重点实验室,上海201800 [2]中国科学院大学材料科学与光电子学技术学院,北京100049 [3]中国科学院上海光学精密机械研究所空天激光技术与系统部,上海201800

出　　处：《中国激光》2024年第11期325-341,共17页Chinese Journal of Lasers

基　　金：中国科学院战略性先导科技专项B类(XDB21030200)。

摘　　要：以原子喷泉为代表的冷原子微波频标近年来取得了飞速发展。基于激光冷却技术的喷泉钟通过原子的抛体运动实现Ramsey干涉,其鉴频谱线约1 Hz的窄线宽和优异的信噪比使得喷泉频标的长期稳定度和不确定度达到了10^(-16),其优异的稳定度指标也对振荡器提出了更高要求。基于光频标技术发展的光生微波可以实现10^(-15)的秒稳定度,从而使喷泉钟的稳定度达到了量子投影噪声极限。通过将性能优异的喷泉钟引入守时钟组,世界原子时的频率精度达到了约2×10^(-16)。除了地面应用外,冷原子频标还进入空间,获得了优异的性能指标,并将在导航定位和科学研究等领域发挥重要作用。中国科学院上海光学精密机械研究所在喷泉频标、光生微波等冷原子微波频标领域开展了系统研究,技术指标达到了国际先进水平,并实现了国际首台空间冷原子钟在轨运行。Significance Time measurement plays an irreplaceable role in modern society,not only in frontier basic research and high-tech fields but also in positioning and navigation,electricity,finance,geodesy,and other fields where it is the core of the technical foundation.The basis of time measurement—the time unit second is defined by atomic time and generated by atomic frequency standards.In recent years,atomic frequency standards have undergone rapid development,and their performance indicators have continuously improved,driving great progress in related fields of precision measurement.Typical examples include the global satellite navigation system based on time measurement achieving sub-meter level positioning accuracy,the time unit second becoming the most accurate and fundamental standard unit among the seven basic units of the International System of Units,and playing an important role in the quantum transformation of the International System of Units.These advances have directly affected all aspects of life.Atomic frequency standards have continuously improved the uncertainty by one order of magnitude every 20 years since they were established in the 1950s.The earliest highest standard was the cesium atomic beam,which had a level of 10-14.In the 1980s,laser cooling enabled atomic frequency standards to achieve a technological leap,giving birth to cold atom frequency standards represented by atomic fountains.This technology effectively reduced the atomic loss caused by thermal motion,and parabolic motion significantly increased the coherence time.Combined with high-sensitivity optical detection and other technologies,the uncertainty of fountain frequency standards was improved to the level of 10^(-16).At the end of the last century,optical frequency standards emerged,and by raising the working spectral lines from the microwave band to the optical band,frequency measurement achieved another technological leap.The uncertainty of frequency standards,which decreased by two orders of magnitude,reached 10^(-18).Howev

关 键 词：时间频率 喷泉频标 稳定度 B类不确定度 空间冷原子钟 光生微波 

分 类 号：TH714.14[机械工程—测试计量技术及仪器]