[1] N D Lemke, K W Martin, R Beard et al. Measurement of optical rubidium clock frequency spanning 65 days. Sensors, 22, 1982(2022).

[2] Y L Liu, W Li, T F Wu et al. Research progress of chip scale atomic clock. Metrol Meas Technol, 41, 7(2021).

[3] M Hasegawa, R K Chutani, C Gorecki et al. Microfabrication of cesium vapor cells with buffer gas for MEMS atomic clocks. Sens Actuat A, 167, 594(2011).

[4] D Budker, M Romalis. Optical magnetometry. Nat Phys, 3, 227(2007).

[5] D V Brazhnikov, S M Ignatovich, I S Mesenzova et al. Nonlinear enhanced-absorption resonances in compact alkali-vapor cells for applications in quantum metrology. J Phys: Conf Ser, 1859, 012019(2021).

[6] T G Walker, W Happer. Spin-exchange optical pumping of noble-gas nuclei. Rev Mod Phys, 69, 629(1997).

[7] J C Allred, R N Lyman, T W Kornack et al. High-sensitivity atomic magnetometer unaffected by spin-exchange relaxation. Phys Rev Lett, 89, 130801(2002).

[8] S Tsvetkov, S Gateva, E Mariotti. Optical control of high-density alkali atom vapor in antirelaxation coated cells. J Phys: Conf Ser, 1859, 012055(2021).

[9] K Shun, H Yoshikazu, T Osamu et al. Microfabricated alkali metal vapor cells filled with an on-chip dispensing component. Jpn J Appl Phys, 60, SCCL01(2021).

[10] S Jia, Z Y Jiang, B B Jiao et al. The microfabricated alkali vapor cell with high hermeticity for chip-scale atomic clock. Appl Sci, 12, 436(2022).

[11] Y C Li, X W Hu, Z J Liu et al. Research progress of atom vapor cell for chip-scale atomic clock. Laser Optoelectron Prog, 55, 060003(2018).

[12] [12] GJB548B-2005. Test methods and procedures for microelectronic device. 2006

[13] Z You, B Ma, Y Ruan et al. Microfabrication of MEMS alkali metal vapor cells for chip-scale atomic devices. Opt Precis Eng, 21, 1440(2013).

[14] J Kitching. Chip-scale atomic devices. Appl Phys Rev, 5, 031302(2018).

[15] B Piccolo, R T O’Connor. Atomic absorption spectroscopy. J Am Oil Chem Soc, 45, 789(1968).

[16] M V Romalis, E Miron, G D Cates. Pressure broadening of Rb D1 and D2 lines by 3He, 4He, N 2, and Xe: Line cores and near wings. Phys Rev A, 56, 4569(1997).

[17] [17] Zhou Y M. Measurement and analysis of alkali-metal-atom density distribution in gyroscopes. Master Dissertation, East China Normal University, 2020 (in Chinese)

[18] [18] Yang J. Study and exploration on physics package of coherent population trapping atomic clock. PhD Dissertation, University of Chinese Academy of Sciences, Wuhan Institute of Physics and Mathematics, 2014 (in Chinese)

[19] [19] Steck D A. Rubidium 85 D line data. Revision 2.1. 6, 2013