[1] K. P. Driedger, R. M. Ifflander, and H. Weber, IEEE J. Quantum Electron. 24, 665 (1988).

[2] M. Kumkar, B. Wedel, and K. Richter, Optics & Laser Technol. 24, 67 (1992).

[3] W. Koechner, Solid-State Laser Engineering (Springer-Verlag, New York, Heidelberg, 1995).

[4] W. H. Carter, Appl. Opt. 19, 1027 (1980).

[5] Q. Li, H. Lei, M. S. Huang, Z. S. Yu, Z. Y. Wang, and T. C. Zuo, Chin. J. Lasers 29, 257 (2002).

[6] D. Wright, P. Greve, J. Fleischer, and L. Austin, Opt. & Quantum Electron. 24, 993 (1992).