[1] F. Xu, J. Liu, R. Li, and Z. Xu, Chin. Opt. Lett. 5, 490 (2007).
[2] S. W. Chan, K. K. Chow, and C. Shu, Acta Opt. Sin. (in Chinese) 23, (suppl.) 395 (2003).
[3] S. V. Chernikov, E. M. Dianov, D. J. Richardson, and D. N. Payne, Opt. Lett. 18, 476 (1993).
[4] H. Zhang, K. Xie, and H. Jiang, Chinese J. Lasers (in Chinese) 35, 1951 (2008).
[5] C. Wang, Chinese J. Lasers (in Chinese) 33, 1630 (2006).
[6] G. P. Agrawal, Nonlinear Fiber Optics (2nd edn.) (Academic, New York, 1995).
[7] K. Shiraki, M. Ohashi, and M. Tateda, Electron. Lett. 31, 668 (1995).
[8] K. Shiraki, M. Ohashi, and M. Tateda, J. Lightwave Technol. 14, 50 (1996).
[9] N. Yoshizawa and T. Imai, J. Lightwave Technol. 11, 1518 (1993).
[10] Y. Imai and N. Shimada, IEEE Photon. Technol. Lett. 5, 1335 (1993).
[11] D. Cotter, Electron. Lett. 18, 504 (1982).
[12] N. A. Olsson and J. P. Van Der Ziel, J. Lightwave Technol. 5, 147 (1987).
[13] Y. Aoki, K. Tajima, and I. Mito, J. Lightwave Technol. 6, 710 (1988).
