[1] T. Yokozawa, and H. Hara, Appl. Opt. 35, 1424 (1996).
[2] G. J. Koch, B. W. Barnes, M. Petros, J. Y. Beyon, F. Amzajerdian, J. Yu, R. E. Davis, S. Ismail, S. Vay, M. J. Kavaya, and U. N. Singh, Appl. Opt. 43, 5092 (2004).
[3] V. Wulfmeyer, M. Randall, A. Brewer, and R. M. Hardesty, Opt. Lett. 25, 1228 (2000).
[4] T. Bilici, O. Tabakoglu, H. Kalaycloglu, A. Kurt, A. Sennaroglu, and M. Gulsoy, in CLEO/Europe and EQEC 2009 Conference Digest CL P11 (2009).
[5] H. Jel nkova, P. Koranda, J. Sulc, M. Nemec, P. Cerny, and J. Pasta, Proc. SPIE 6871, 68712N (2008).
[6] C. Wu, Y. Ju, Y. Li, Z. Wang, and Y. Wang, Chin. Opt. Lett. 6, 594 (2008).
[7] Y. Li, B. Yao, Y. Wang, Y. Ju, G. Zhao, Y. Zong, and J. Xu, Chin. Opt. Lett. 5, 286 (2007).
[8] E. H. Bernhardi, A. Forbes, C. Bolig, and M. J. D. Esser, 16, 11115 (2008).
[9] W.-J. He, B.-Q. Yao, Y.-Z. Wang, and Y.-L. Ju, Acta Phys. Sin. (in Chinese) 56, 3240 (2007).
[10] X.-L. Zhang, Y.-Z. Wang, and H.-F. Shi, Acta Phys. Sin. (in Chinese) 55, 1787 (2006).
[11] T. Li, S. Zhao, Z. Zhuo, and Y. Wang, Opt. Commun. 282, 940 (2009).
[12] C. Pfistner, R. Weber, H. P. Weber, S. Merazzi, and R. Gruber, IEEE J. Quantum Electron. 30, 1605 (1994).
[13] B. Yao, X. Duan, Y. Li, L. Zheng, Y. Wang, G. Zhao, and J. Xu, Chin. Opt. Lett. 6, 520 (2008).
[14] Y. Lu, Y. Dai, Y. Yang, J. Wang, A. Dong, and B. Sun, J. Alloy. Compd. 453, 482 (2008).
[15] P. Cerny and D. Burns, IEEE J. Sel. Top. Quantum Electron. 11, 674 (2006).
[16] M. E. Innocenzi, H. T. Yura, C. L. Fincher, and R. A. Fields, Appl. Phys. Lett. 56, 1631 (1990).