[1] W.-H. Lee, Opt. Commun. 36, 469 (1981).

[2] C.-Y. Han, Y. Ishii, and K. Murata, Appl. Opt. 22, 3644 (1983).

[3] S. K. Dew and R. R. Parsons, Appl. Opt. 31, 3416 (1992).

[4] C. Xie, R. Gupta, and H. Metcalf, Opt. Lett. 18, 173 (1993).

[5] J. X. Pu and H. H. Zhang, Appl. Opt. 37, 4200 (1998).

[6] J. A. Hoffnagle and C. M. Jefferson, Appl. Opt. 39, 5488 (2000).

[7] D. Shafer, Opt. Laser Technol. 14, 159 (1982).

[8] B. D. Lu and H. Ma, Opt. Commun. 171, 185 (1999).

[9] Y. J. Li, Opt. Lett. 27, 1007 (2002).