[1] [1] T. L. Nicholson, M. J. Martin, J. R. Williams et al.. Comparison of two independent Sr optical clocks with 1×10-17 stability at 103 s［J］. Phys. Rev. Lett., 2012, 109(23): 230801

[2] [2] A. D. Ludlow, T. Zelevinsky, G. K. Campbell et al.. Sr lattice clock at 1×10-16 fractional uncertainty by remote optical evaluation with a Ca clock ［J］. Science, 2008, 319(5871): 1805～1808

[3] [3] H. Katori, T. Ido, Y. Isoya at al.. Magneto-optical trapping and cooling of strontium atoms down to the photon recoil temperature［J］. Phys. Rev. Lett., 1999, 48(6): 1116～1119

[4] [4] K. R. Vogel, T. P. Dinneen, A. Gallagher et al.. Narrow-line doppler cooling of strontium to the recoil limit［J］. IEEE Transaction on Instrumentation and Measurement., 1999, 48(2): 618～621

[5] [5] P. G. Mickelson, Y. N. Martinez de Escobar, M. Yan et al.. Bose-einstein condensation of 88Sr though sympathetic cooling with 87Sr［J］. Phys. Rev. A, 2010, 81(5): 051601

[6] [6] S. Blatt. Ultracold Collisions and Fundamental Physics with Strontium［D］. Colorado: University of Colorado, 2011. 1～3

[7] [7] G. M. Tino, M. Barsanti, M. de Angelis et al.. Spectroscopy of 689 nm intercombination line of strontium using an extended-cavity InGaP/InGaAIP diode laser［J］. Appl. Phys. B, 1992, 55(4): 379～400

[8] [8] W.Demtrder. Laser Spectroscopy Vol.2:Experimental techniques ［M］. 4th ed. Springer, 2008. 175～178

[9] [9] Y. N. Martinez. Studies of the 5s2 1S0-5s5p 3P1 Transition in Atomic Strontium［D］. Houston: Rice University, 2008. 4～5

[10] [10] M. M. Boyd. High Precision Spectroscopy of Strontium in an Optical Lattice: Towards a New Standard for Frequency and Time［D］. Colorado: University of Colorado, 2007. 118～122

[11] [11] Wang Yiqiu, Wang Qinji, Fu Jishi et al.. Principle of Quantum Frequency Standards［M］. Beijing: Science Press, 1986. 283～289

[12] [12] R. Fritz. Frequency Standards Basics and Applications ［M］. Weinheim: Wiley-VCH Press, 2004. 149～153

[13] [13] C. E. Wieman, L. Hollberg. Using diode lasers for atomic physics［J］. Rev. Sci. Instrum., 1991, 62(1): 1～20

[14] [14] W. Demtrder. Laser Spectroscopy Vol.1:Basic and Principles ［M］. 4th ed. Springer, 2008. 85～93

[15] [15] Tian Xiao, Wang Xinliang, Chang Hong et al.. Trapping four isotopes of strontium in a MOT by using Zeeman slowing［J］. Acta Optica Sinica, 2010, 30(3): 898～902

[16] [16] I. Courtillot, A. Quessada-Vial, A. Brusch et al.. Accurate spectroscopy of Sr atoms［J］. Eur. Phys. J. D., 2005, 33: 161～171

[17] [17] G. Ferrari, P. Cancio, R. Drullinger et al.. Precision frequency measurement ofvisible intercombination lines of strontium［J］. Phys. Rev. Lett., 2003, 91(24): 243002

[18] [18] S. B. Negel. A Narrow Linewidth Diode Laser System for Strontium Laser Cooling Applications［D］. Houston: Rice University, 2004. 22～23

[19] [19] Gao Kelin. Optical frequency standards based on trapped ions ［J］. Physics, 2010, 39(9): 604～611