氢钟测量死时间导致的光频测量统计不确定度分析  

Analysis of Statistical Uncertainty of Optical Frequency Measurement Due to Measurement Dead Time of Hydrogen Maser

作　　者：陈樱鑫 卢晓同 常宏[1,2,3] Chen Yingxin;Lu Xiaotong;Chang Hong(Key Laboratory of Time and Frequency Primary Standards,National Time Service Center,Chinese Academy of Sciences,Xi'an 710600,Shaanxi,China;Hefei National Laboratory,Hefei 230088,Anhui,China;School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院国家授时中心时间频率基准重点实验室,陕西西安710600 [2]合肥国家实验室,安徽合肥230088 [3]中国科学院大学天文与空间科学学院,北京100049

出　　处：《光学学报》2023年第13期134-139,共6页Acta Optica Sinica

基　　金：国家自然科学基金(12203057);中国科学院战略性先导科技专项(B类)(XDB35010202)。

摘　　要：利用87Sr光晶格钟与氢钟的频率比对测量了氢钟的频率稳定度。在89%的光晶格钟有效运行率下,经过约10 d的测量得出氢钟的频率稳定度,并由此推导出氢钟噪声模型的相关参数。根据氢钟噪声模型生成的随机噪声序列,对由测量死时间导致的频差进行了100次模拟,并以模拟结果的1倍标准差为测量不确定度。不同有效运行率下,氢钟测量不确定度的计算结果表明,由氢钟测量死时间导致的不确定度随有效运行率的增加而减小,且在有效运行率小于10%时,增加总的测量时间可以显著减小测量不确定。Objective Optical clocks have developed rapidly in the past 20 years and have achieved a systematic uncertainty of 9.4×10^(-19) and frequency stability of 4.8×10^(-17)@1 s.Except for the generation of standard time and frequency,optical clocks have many important applications,such as verification of general relativity,measurement of possible variation of the fine structure constant with time,detection of ultralight bosonic dark matter,quantum simulation,and relativistic geodesy.As more and more systematic uncertainty of the optical clock enters the order of 10^(-18),and the absolute frequency measurement accuracy of the optical clock is fundamentally limited by the systematic uncertainty of the ^(133)Cs fountain clock,it has been proposed to use optical frequency transition to redefine the second in the international system of units.The 27th General Conference of Weights and Measures(CGPM)officially passed a resolution:The 28th CGPM will be held in 2026 to discuss the choice of optical clock types for redefining the second,and the optical frequency transition will be formally used to define the second expected in 2030.One of the main methods of absolute frequency measurement of optical clocks is to trace the international atomic time through a satellite link,and measurement uncertainty of less than 3×10^(-16) is a precondition for the redefinition of the second in the international system of units by the optical frequency transition.In this complex tracing link,the uncertainty caused by the measurement dead time of the hydrogen maser is one of the main sources of absolute frequency measurement uncertainty for most optical clocks.After removing the contribution of frequency drift of the hydrogen maser,the statistical uncertainty caused by the measurement dead time of the hydrogen maser can be obtained by numerical simulation.This method needs to know the relevant parameters of the noise model of the hydrogen maser accurately and then generate the relevant random noise sequences by software.Methods In this paper

关 键 词：测量 光频测量 氢钟噪声模型 光晶格钟 稳定度 

分 类 号：O562.5[理学—原子与分子物理]