[1] J. Capmany, B. Ortega and D. Pastor, Journal of Lightwave Technology 24, 201 (2006).
[2] J. Yao, Journal of Lightwave Technology 27, 314 (2009).
[3] Capmany J., Mora J., Gasulla I., Sanchi J., Lloret J. and Sales S., Journal of Lightwave Technology 31, 571 (2013).
[4] Minasian R. A., Chan E. H. W. and Yi X., Optics Express 21, 22918 (2013).
[5] En-ming Xu, Qi Wang, Fei Wang and Pei-li Li, Optoelectronics Letters 10, 374 (2014).
[6] Ai-ling Zhang, Cong Huang and Xiao-jun Wu, Optoelectronics Letters 10, 5 (2014).
[7] Xu X., Ou H. and Wong K., IEEE Photonics Technology Letters 26, 893 (2014).
[8] Feng X., Lu C., Tam H. Y. and Wai P. K. A., IEEE Photonics Technology Letters 19, 1334 (2007).
[9] Xue X., Zheng X., Zhang H. and Zhou B., Optics Express 20, 26929 (2012).
[10] C. Zhang, L.-S. Yan, W. Pan, B. Luo, X.-H. Zou, H.-Y. Jiang and B. Lu, IEEE Photonics Journal 5, 5501606 (2013).
[11] W. Zhang and R. A. Minasian, IEEE Photonics Technology Letters 24, 1182 (2012).
[12] W. Li, L. X. Wang and N. H. Zhu, IEEE Photonics Journal 5, 5501411 (2013).
[13] M. Sagues, R. Garcia Olcina, A. Loayssa, S. Sales and J. Capmany, Optics Express 16, 295 (2008).
[14] W. Li, N. H. Zhou and L. X. Huang, IEEE Photonics Journal 3, 462 (2011).
[15] Y.Yan and J.Yao, IEEE Photonics Technology Letters 19, 1472 (2007).
[16] Y. Wang, E. H. W. Chan, X. Wang, X. Feng and B. Guan, IEEE Photonics Journal 7, 5500311 (2015).