[1] Z. X. Liao, F. Yang, and W. J. Xia, Laser Journal (in Chinese) 25, 10 (2004).
[2] H. Yin, X. C. Ying, and J. Zong, Infrared Laser Eng. (in Chinese) 37, 723 (2008).
[3] M. P. Zhu, K. Yi, S. H. Guo, Z. X. Fan, and J. D. Shao, Acta Opt. Sin. (in Chinese) 26, 1107 (2006).
[4] W. X. Fan, Z. G. Zhao, P. Q. Wang, J. L. Zhou, and Z. Ma, Laser Technology (in Chinese) 30, 320 (2006).
[5] A. Zoeller, M. Boos, R. Goetzelmann, H. Hagedorn, and W. Klug, Proc. SPIE 5963, 59630D (2005).