[1] Clairon A, Salomon C, Guellati S et al. Ramsey resonance in a Zacharias fountain[J]. Europhysics Letters (EPL), 16, 165-170(1991).

[2] Vian C, Rosenbusch P, Marion H et al. BNM-SYRTE fountains: recent results[J]. IEEE Transactions on Instrumentation and Measurement, 54, 833-836(2005).

[3] Guéna J, Abgrall M, Rovera D et al. Progress in atomic fountains at LNE-SYRTE[J]. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 59, 391-409(2012).

[4] Liu L, Lu D S, Chen W B et al. In-orbit operation of an atomic clock based on laser-cooled 87Rb atoms[J]. Nature Communications, 9, 2760(2018).

[5] Micalizio S, Godone A, Levi F et al. Pulsed optically pumped 87Rb vapor cell frequency standard: a multilevel approach[J]. Physical Review A, 79, 013403(2009).

[6] Sortais Y, Bize S, Nicolas C et al. Cold collision frequency shifts in a 87Rb atomic fountain[J]. Physical Review Letters, 85, 3117-3120(2000).

[7] Peng X K, Ren W, Xiang J F et al. Performance analysis of space cold atomic clock based on in situ atomic detection[J]. Acta Optica Sinica, 39, 0802001(2019).

[8] Wang Q, Wei R, Wang Y Z. Atomic fountain frequency standard: principle and development[J]. Acta Physica Sinica, 67, 163202(2018).

[9] Guo F, Kong D H, Zhang Q et al. System development and clock transition spectroscopy detection of transportable 87Sr optical clock[J]. Acta Optica Sinica, 40, 0902001(2020).

[10] Li T C, Li M S, Lin P W et al[J]. Experiments and considerations of realizing cold cesium atomic 74 cm fountain Acta Metrologica Sinica, 2003, 254-256.

[11] Li C, Chen H C, Lin Y G et al[J]. Design of signal generator applied on sideband modulation pound-drever-hall laser frequency stabilization Acta Metrologica Sinica, 2018, 401-404.

[12] Guo Y, Qiu Q, Wang Y X et al. Research on stability of Fabry-Perot cavity based on PDH[J]. Chinese Journal of Lasers, 43, 0402003(2016).

[13] Han L, Lin Y G, Yang J et al. Research and development on laser frequency stabilization based on spectral hole-burning effect[J]. Laser & Optoelectronics Progress, 56, 110003(2019).

[14] Zhang Y, Wang Q. Research of automatic frequency stability diode laser[J]. Chinese Journal of Lasers, 41, 0602001(2014).

[15] Wang X W, Xiang J F, Peng X K et al. Light source of rubidium cold atomic clock based on fiber laser amplification and frequency doubling[J]. Acta Optica Sinica, 39, 0914002(2019).

[16] Talvitie H, Pietilainen A, Ludvigsen H et al. Passive frequency and intensity stabilization of extended-cavity diode lasers[J]. Review of Scientific Instruments, 68, 1-7(1997).

[17] Ren W, Sun Y G, Wang B et al. Highly reliable optical system for a rubidium space cold atom clock[J]. Applied Optics, 55, 3607-3614(2016).