[1] V. A. Kozlov, J. Hern'andez-Cordero, and T. F. Morse, Opt. Lett. 24, 1814 (1999).
[2] T. B. Simpson, A. Gavrielides, and P. Peterson, Opt. Express 10, 1060 (2002).
[3] A. Shirakawa, T. Saitou, T. Sekiguchi, and K. Ueda, Opt. Express 10, 1167 (2002).
[4] D. Sabourdy, V. Kermène, A. Desfarges-Berthelemot, L. Lefort, and A. Barthelem, Opt. Express 11, 87 (2003).
[5] S. Chen, Y. Li, and K. Lu, Opt. Express 13, 7878 (2005).
[6] F. Liu, X. Jia, Y. Liu, S. Yuan, and X. Dong, Chin. Phys. Lett. 24, 929 (2007).
[7] J. Hou, R. Xiao, Z. Jiang, X. Cheng, B. Shu, J. Cheng, and Z. Liu, Chin. Phys. Lett. 22, 2273 (2005).
[8] J. Hou and R. Xiao, Chin. Phys. Lett. 23, 3288 (2006).
[9] M. Song, B. Zhao, and X. Zhang, Chin. Opt. Lett. 3, 271 (2005).
[10] W. W. Rigrod, IEEE J. Quantum. Electron. 6, 9 (1970).
[11] Y. Liu, X. Feng, L. Li, Y. Li, S. Yuan, G. Kai, Y. Li, and X. Dong, Chin. Phys. Lett. 22, 343 (2005).