Improvement of the short-term stability of atomic fountain clock with state preparation by two-laser optical pumping  

作　　者：Lei Han Fang Fang Wei-Liang Chen Kun Liu Shao-Yang Dai Ya-Ni Zuo and Tian-Chu Li 韩蕾;房芳;陈伟亮;刘昆;戴少阳;左娅妮;李天初(School of Optics and Photonics,Beijing Institute of Technology,Beijing 100081,China;Key Laboratory of Time and Frequency Standards,National Institute of Metrology(NIM),Beijing 100029,China)

机构地区：[1]School of Optics and Photonics,Beijing Institute of Technology,Beijing 100081,China [2]Key Laboratory of Time and Frequency Standards,National Institute of Metrology(NIM),Beijing 100029,China

出　　处：《Chinese Physics B》2021年第5期272-276,共5页中国物理B（英文版）

基　　金：the National Natural Science Foundation of China(Grant No.11873044).

摘　　要：To improve the signal to noise ratio(SNR)and the short-term stability of cesium atomic fountain clocks,the work of two-laser optical pumping is presented theoretically and experimentally.The short-term stability of the NIM6 fountain clock has been improved by preparing more cold atoms in the|F=4,m_(F)=0>clock state with a shortened cycle time.Two π-polarized laser beams overlapped in the horizontal plane have been applied after launching,one is resonant with|F=4>→|F′=4>transition and the other is resonant with|F=3>→|F′=4>transition.With optical pumping,the population accumulated in the|m_(F)=0>clock state is improved from 11%to 63%,and the detection signal is increased by a factor of 4.2,the SNR of the clock transition probability and the short-term stability are also improved accordingly.

关 键 词：optical pumping atomic fountain clock SPIN-POLARIZATION short-term stability 

分 类 号：TH714[机械工程—测试计量技术及仪器] TN249[机械工程—仪器科学与技术]