Improving the short-term frequency stability of a magnetic-state-selected cesium beam clock with optical detection

Chang Liu; Sifei Chen; Ziyu Chen; Lingxiang Li; Shaohang Xu; Yining Li; Jiale Wang; Yanhui Wang; Shimin Hou; Jun Zhang; Richang Dong; Xiaobo Jiang

doi:10.1063/5.0046575

Improving the short-term frequency stability of a magnetic-state-selected cesium beam clock with optical detection

Rev Sci Instrum. 2021 Jul 1;92(7):073302. doi: 10.1063/5.0046575.

Authors

Chang Liu¹, Sifei Chen², Ziyu Chen², Lingxiang Li², Shaohang Xu², Yining Li², Jiale Wang², Yanhui Wang¹, Shimin Hou³, Jun Zhang⁴, Richang Dong⁴, Xiaobo Jiang⁴

Affiliations

¹ State Key Laboratory of Advanced Optical Communication Systems and Networks, Department of Electronics, Peking University, Beijing 100871, China.
² Department of Electronics, Institute of Quantum Electronics, Peking University, Beijing 100871, China.
³ Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, China.
⁴ Key Laboratory of Microsatellites, Chinese Academy of Sciences, Shanghai 201203, China.

PMID: 34340434
DOI: 10.1063/5.0046575

Abstract

The microwave spectrum line shape and the signal-to-noise ratio of a compact optically detected magnetic-state-selection cesium beam clock are analyzed in this paper. As the noise analysis shows, the performance is related to the atomic utilization ratio and locking parameters when the laser frequency noise is the dominant noise source. Methods are adopted for realizing better short-term frequency stability of the clock, including using a highly efficient state-selection cesium beam tube, optimizing the locking parameters, and stabilizing the microwave power to maximize the error signal. After optimization, the signal-to-noise ratio of the clock reaches 7.0 × 10³ in a bandwidth of 1 Hz and the clock demonstrates a short-term stability of 4.1 × 10^-12 τ^-1/2. The five-day Allan standard deviation reaches 7.7 × 10^-15.