[1] Y. Jeong, J. K. Sahu, D. N. Payne, J. Nilsson. Opt. Express, 12, 6088(2004).
[2] V. Gapontsev, D. Gapontsev, N. Platonov, O. Shkurkhin, V. Fomin, A. Mashkin, M. Abramov, S. Ferin. Proceedings of the Conference on Lasers and Electro-Optics Europe(2005).
[4] B. Zhao, K. Duan, W. Zhao, C. Li, Y. Wang. Chin. Opt. Lett., 8, 404(2010).
[6] Z. Wang, Q. Li, Z. Wang, F. Zou, Y. Bai, S. Feng, J. Zhou. Chin. Opt. Lett., 14, 081401(2016).
[8] J. Nilsson. Proceedings of the Conference on Lasers and Electro-Optics, CTuC1(2010).
[9] D. J. Richardson, J. Nilsson, W. A. Clarkson. J. Opt. Soc. Am. B, 27, B63(2010).
[10] J. P. Hao, P. Yan, Q. R. Xiao, D. Li, M. L. Gong. Chin. Phys. B, 23, 014203(2014).
[12] V. Fomin, M. Abramov, A. Ferin, A. Abramov, D. Mochalov, N. Platonov, V. Gapontsev. 5th International Symposium on High-Power Fiber Lasers and Their Applications(2010).
[13] E. Stiles. 5th International Workshop on Fiber Lasers(2009).
[15] H. Xiao, P. Zhou, X. L. Wang, X. J. Xu, Z. J. Liu. Laser Phys. Lett., 10, 065102(2013).
[16] X. Hu, J. Y. Leng, H. W. Zhang, L. J. Huang, J. M. Xu, P. Zhou. Appl. Opt., 54, 8166(2015).
[18] Z. Li, J. Zhou, B. He, X. Gu, Y. Wei, J. Dong, Q. Lou. Chin. Opt. Lett., 9, 091401(2011).
[19] A. D. Yablon. Optical Fiber Fusion Splicing(2005).
[20] I. Kelson, A. A. Hardy. IEEE J. Quantum Lett., 34, 1570(1998).
[21] I. Kelson, A. A. Hardy. IEEE J. Lightwave Technol., 17, 891(1999).