[1] L. Luo and P. L. Chu, Opt. Commun. 161, 257 (1999).
[2] H. H. Kee, G. P. Lees, and T. P. Newson, Electron. Lett. 34, 1318 (1998).
[3] P. Roy, D. Pagnoux, L. Mouneu, and T. Midavaine, Electron. Lett. 33, 1317 (1997).
[4] J. Li, Y. Guo, T. Wang, Y. Sun, B. Bai, X. Li, and G. Hu, Chin. Opt. Lett. 1, 503 (2003).
[5] P. K. Cheo, IEEE Photon. Technol. Lett. 13, 188 (2001).
[6] J. Nilsson, S.-U. Alam, J. A. Alvarez-Chavez, P. W. Turner, W. A. Clarkson, and A. B. Grudinin, IEEE J. Quantum Electron. 39, 987 (2003).
[7] Y. Wang, Y. Zheng, H. Shen, L. Yang, W. Zhao, and G. Chen, Acta Photon. Sin. (in Chinese) 32, 1025 (2003).
[8] W. Xiang, L. Zhang, X. Pei, T. Xue, and G. Zhang, J. Optoelectronics Laser 14, 1015 (2003).
[9] W. Koechner, Solid-State Laser Engineering (Springer-Verlag, Berlin, 1996).
