[1] L. X. Chen and D. Kima, Opt. Commun. 218, 19 (2003).

[2] G. Molina-Terriza, J. P. Torres, L. Torner, and J. M. Soto-Crespo, Opt. Commun. 158, 170 (1998).

[3] J. A. Gaspar-Armenta and F. Villa, Opt. Commun. 216, 379 (2003).

[4] M. Born and E. Wolf, Principles of Optics (Cambridge University Press, New York, 1999).

[5] X. D. Liu, Y. Q. Wang, B. Y. Cheng, and D. Z. Zhang, Phys. Rev. E 68, 036610 (2003).

[6] N. H. Liu, S. Y. Zhu, H. Chen, and X. Wu, Phys. Rev. E 65, 046607 (2002).