[1] B. Dong, J. Z. Hao, C. Y. Liaw, B. Lin and S. C. Tjin, Applied Optics 49, 6232 (2010).
[2] B. O. Guan, H. Y. Tam, S. L. Ho, W. H. Chung and X. Y.Dong, Electron. Lett. 26, 1018 (2000).
[3] T. Wei, X. G. Qiao and Z. A. Jia, Optoelectronics Letters 7,0026 (2011).
[4] T. T. Han, Y. G. Liu and Z. Wang, Journal of Optoelectronics Laser 23, 215 (2012). (in Chinese)
[5] S. M. Lee, M. Y. Jeong and S. S. Saini, Journal of Lightwave Technology 30, 1025 (2012).
[6] Z. Y. Zhang, L. S. Yan and W. Pan, Sensors 12, 3891 (2012).
[7] J. B. Xu, Y. G. Liu, Z. Wang and B.Tai, Applied Optics 49,492 (2010).
[8] Q. Y. Chen, S. H. Shi, Z. Y. Zhang, K. Fang and X. J. Zhou,Journal of Optoelectronics Laser 22, 677 (2011). (inChinese)
[9] A. Sun and Z. S. Wu, Optical Engineering 51, 1117 (2012).
[10] K. Zhang and S. Wang, Journal of Optoelectronics Laser 23, 15 (2012). (in Chinese)
[11] Q. Z. Rong, X. G. Qiao and J. Zhang, Journal of Lightwave Technology 30, 1645 (2012).