[1] M. Presi, R. Corsini, M. Artiglia, E. Ciaramella. Opt. Express, 23, 22706(2015).

[2] Z. Zhang, X. Jiang, J. Wang, X. Chen, L. Wang. Chin. Opt. Lett., 13, 020603(2015).

[3] O. Ozolins, V. Bobrovs. Chin. Opt. Lett., 13, 060603(2015).

[4] C. Li, X. Qiu, X. Li. Photon. Res., 5, 97(2017).

[5] H. S. Chung, B. K. Kim, K. Kim. ETRI J., 30, 255(2008).

[6] X. F. Cheng, Y. K. Yeo, Z. W. Xu, Y. X. Wang. European Conference and Exhibition on Optical Communication, 20(2009).

[7] J. Zhao, L. K. Chen, C. K. Chan. Optical Fiber Communication Conference and the National Fiber Optic Engineers Conference, OWD(2007).

[8] J. Xu, L. K. Chen. IEEE Photon. Technol. Lett., 22, 456(2010).

[9] C. W. Chow, Y. Liu, C. Kwok. Optical Fiber Communication Conference and the National Fiber Optic Engineers Conference, OTHT2(2008).

[10] J. Prat, V. Polo, C. Bock, C. Arellano. IEEE Photon. Technol. Lett., 17, 702(2005).

[11] A. Chowdhury, H. C. Chien, M. F. Huang, J. Yu. IEEE Photon. Technol. Lett., 20, 2081(2008).

[12] J. Xu, L. K. Chen. Optical Fiber Communication Conference and the National Fiber Optic Engineers Conference, OThG3.(2010).

[13] J. Xu, X. Y. Yu, W. C. Lu, F. Z. Qu, N. Deng. Opt. Commun., 346, 106(2015).

[14] X. Liu, A. H. Gnauck, X. Wei, J. Y. C. Hsieh, V. Chien. IEEE Photon. Technol. Lett., 17, 2610(2005).

[15] H. Feng, S. Xiao, Q. Zhou, J. Ge, M. Fok. Opt. Express, 22, 22673(2014).

[16] K. Y. Cho, U. H. Hong, S. P. Jung, Y. Takushima, A. Agata, T. Sano, Y. Horiuchi, M. Suzuki, Y. C. Chung. Opt. Express, 20, 15353(2012).

[17] C. W. Chow, C. H. Yeh, L. Xu, H. K. Tsang. IEEE Photon. Technol. Lett., 22, 1294(2010).

[18] C. W. Chow, G. Talli, A. D. Ellis, P. D. Townsend. Opt. Express, 16, 1860(2008).

[19] H. He, J. Li, M. Bi, W. Hu. Chin. Opt. Lett., 12, 040603(2014).

[20] E. Hugues-Salas, R. Giddings, X. Jin, J. Wei, X. Zheng, Y. Hong, C. Shu, J. Tang. Opt. Express, 19, 2979(2011).

[21] S. Mhatli, M. Ghanbarisabagh, L. Tawade, B. Nsiri, M. Jarajreh, M. Channoufi, R. Attia. Opt. Lett., 39, 6711(2014).