[1] E. Wong, J. Lightwave Technol. 30, 597 (2012).

[2] D. Breuer, F. Geilhardt, R. H¨ulsermann, M. Kind, C. Lange, T. Monath, and E. Weis, IEEE Commun. Mag. 49, S16 (2011).

[3] L. Yi, Z. Li, T. Zhang, D. Lin, Y. Dong, and W. Hu, Chin. Opt. Lett. 9, 120603 (2011).

[4] Q. Guo and A. V. Tran, IEEE Photon. Technol. Lett. 24, 952 (2012).

[5] H. K. Shim, K. Y. Cho, U. H. Hong, and Y. C. Chung, in Proceedings of OFC/NFOEC OW1A. 6 (2013).

[6] J.-I. Kani, J. Sel. Topics Quantum Electron. 16, 1290 (2010).

[7] Q. Guo, A. V. Tran, and C. J. Chae, IEEE Photon. Technol. Lett. 23, 1442 (2011).

[8] M. Omella, V. Polo, J. Lazaro, B. Schrenk, and J. Prat, in Proceedings of ECOC Tu.3.E.4 (2008).

[9] Y. Zhan, M. Zhang, L. Liu, M. Liu, Z. Liu, and X. Chen, Chin. Opt. Lett. 10, 090602 (2012).

[10] J. M. Buset, Z. A. El-Sahn, andD. Plant, in Proceedings OFC/NFOEC NTh4F.1 (2013).

[11] I. Papagiannakis, M. Omella, D. Klonidis, N. Birbas, J. Kikidis, I. Tomkos, and J. Prat, IEEE Photon. Technol. Lett. 20, 2168 (2008).

[12] M. Presi, R. Corsini, A. Chiuchiarelli, F. Bottoni, G. Cossu, L. Giorgi, P. Choudhury, and E. Ciaramella, in Proceedings of OFC/NFOEC OW1A.7 (2013).

[13] A. Agata and Y. Horiuch, in Proceedings of OFC/NFOEC OWG3 (2010).

[14] Q..i Guo, A. V. Tran, and C.-J. Chae, in Proceedings of OFC NTuB5 (2011).

[15] H. Kim, in Proceedings of OFC/NFOEC OMP8 (2011).

[16] Z. Li, L. Yi, M. Bi, J. Li, H. He, X. Yang, and W. Hu, in Proceedings of OFC/NFOEC NTh4F.3 (2013)

[17] J. Yu, Z. Jia, M. Huang, M. Haris, N. J. Philip, T. Wang, and G. Chang, J. Lightwave Technol. 27, 253 (2009).

[18] C. Wang and J. Yao, IEEE Photon. Technol. Lett. 25, 1889 (2013).