[1] Tol P J J, Herschbach N, Hessels E A, et al. Large numbers of cold metastable helium atoms in a magneto-optical trap [J]. Phys. Rev. A, 1999, 60(2): R761-R764.
[2] Shimizu F, Shimizu K, Takuma H. A high intensity metastable neon trap [J]. Chem. Phys., 1990, 145(2): 327-331.
[3] Katori H, Shimizu F. Lifetime measurement of the 1s5 metastable state of argon and krypton with a magneto-optical trap [J]. Phys. Rev. Lett., 1993, 70(23): 3545-3548.
[4] Walhout M, Megens H J L, Witte A, et al. Magneto-optical trapping of metastable xenon: isotope-shift measurements [J]. Phys. Rev. A, 1993, 48(2): R879-R882.
[5] Chen C Y, Li Y M, Bailey K, et al. Ultrasensitive isotope trace analysis with a magneto-optical trap [J]. Science, 1999, 286: 1139-1141.
[7] Drever R W P, Hall J L, et al. Laser phase and frequency stabilization using an optical resonator [J]. Appl. Phys. B, 1983, 31(1): 97-105.
[13] Bjorklund G C. Frequency-modulation spectroscopy: a new method for measuring weak absorptions and dispersions [J]. Optics Letters, 1980, 5(1): 15-17.
[15] Sakai Y, Yokohama L, Kano G, et al. Frequency stabilized laser diode locked to acetylene gas absorption lines using fiber-pigtail-type acoustic optical modulator [J]. IEEE Photon. Tech. Lett., 1992, 4(1): 96-98.
