[1] F. Buchali and H. Buow, J. Lightwave Technol. 22, 1116 (2004).

[2] L. Xi, X. Zhang, L. Yu, and G. Zhou, Chin. Opt. Lett. 2, 262 (2004).

[3] X. Zhang, L. Xi, L. Yu, and G. Zhou, Chin. Opt. Lett. 2, 316 (2004).

[4] T. Takahashi, T. Imai, and M. Aiki, Electron. Lett. 30, 348 (1994).

[5] F. Buchali, S. Lanne, J.-P. Thiery, and W. Baumert, in Proceedings of OFC'2001 Tup5-1 (2001).

[6] Y. Zheng, B. Yang, and X. Zhang, IEEE Photon. Technol. Lett. 29, 1412 (2002).

[7] J. C. Rasmussen, A. Isomura, and G. Ishikawa, J. Lightwave Technol. 20, 2101 (2002).

[8] H. Rosenfeldt, C. Knothe, U. R. Brinkmeyer, and E. Feiste, in Tech. Dig. OFC'2001 PD27-1 (2001).

[9] C. Xie, L. Moller, R. M. Jopson, and A. H. Gnauck, in Proceedings of OFC'2004 WE4 (2004).

[10] C. Xie and L. Moller, IEEE Photon. Technol. Lett. 17, 570 (2005).

[11] C. D. Poole and R. E. Wagner, Electron. Lett. 22, 1029 (1986).

[12] J. P. Gordon and H. Kogelnik, Proc. Nat. Acad. Sci. 97, 4541 (2000).

[13] Y. Zheng, X. Zhang, G. Zhou, Y. Shen, and L. Chen, IEEE J. Quantum Electron. 40, 427 (2004).

[14] K. Nobuhiko, J. Lightwave Technol. 19, 480 (2001).