[1] [1] J. Mark, L. Y. Liu, K. L. Hall et al.. Femtosecond pulseg eneration in a laser with an onlinear external resonator. Opt. Lett., 1989, 14(1): 48～50

[2] [2] J. Goodberlet, J. Wang, J. G.Fujimoto et al.. Femtosecond passively mode-locked Ti:Al2O3 laser with anonlinear external cavity. Opt. Lett., 1989, 14(20): 1125～1127

[3] [3] E. P. Ippen, H. A. Haus, L. Y. Liu. Additive pulse mode locking. J. Opt. Soc. Am. B, 1989, 6(9): 1736～1745

[4] [4] L. Y. Liu, J. M. Huxley, E. P. Ippen et al.. Self-starting additive-pulse modelocking of a Nd:YAG laser. Opt. Lett., 1990, 15(10): 553～555

[6] [6] Joseph Hamel, Amine Cassimi, Hassan Abu-Safia et al.. Diode pumping of LNA lasers for helium optical pumping. Opt. Comm., 1987, 63(2): 114～117