[1] C. Lim, A. Nirmalathas, M. Bakaul, P. Gamage, K. L. Lee, Y. Z. Yang, D. Novak, and R. Waterhouse, J. Lightwave Technol. 28, 390 (2010).
[2] P. K. Tang, L. C. Ong, A. Alphones, B. Luo, and M. Fujise, J. Lightwave Technol. 22, 2370 (2004).
[3] J. James, P. Shen, A. Nkansah, X. Liang, and N. J. Gomes, IEEE Trans. Micro. Theo. Technol. 11, 3189 (2010).
[4] X. Wu, X. P. Zheng, S. Y. Li, H. Wen, Y. L. Guo, and H. Y. Zhang, IEEE Photon. Technol. Lett. 22, 76 (2010).
[5] S. Y. Li, X. P. Zheng, H. Y. Zhang, and B. K. Zhou, IEEE Photon. Technol. Lett. 22, 1775 (2010).
[6] S. Li, X. Zheng, H. Zhang, and B. Zhou, in Proceedings of Lasers and Electro-Optics (CLEO) JWA3 (2011).
[7] C. Tang, L. Chen, J. Xiao, and Z. Cao, Chin. Opt. Lett. 9, 050601 (2011).
