[1] R. Paschotta, J. Nilsson, A. C. Tropper, et al.. Efficient superfluorescent light sources with broad bandwidth [J]. IEEE J Sel Top Quantum Electron, 1997, 3(4): 1097-1099.

[2] Z Li, J Zhou, B He, et al.. Diode-pumped 1018-nm ytterbium-doped double-clad f iber laser [J]. Chin Opt Lett, 2011, 9(9): 91401.

[3] S Matsubara, K Uno, Y Nakajima, et al.. Extremely low quantum defect oscillation of ytterbium fiber laser by laser diode pumping at room temperature [C]. Advanced Solid-State Photonics, Optical Society of America, 2007, TuB4.

[4] C A Codemard, J Nilsson, J K Sahu. Tandem pumping of large-core double-clad ytterbium-doped fiber for control of excess gain [C]. OSA/ASSP/LACSEA/LS&C, 2010, AWA3.

[5] Zhang Panzheng, Fan Wei, Wang Xiaochao, et al.. Mode-locking and multiwavelength operation from all-fiber ytterbium doped laser [J]. Chinese J Lasers, 2011, 38(3): 0302001.

[6] Chen Bai, Chen Lanrong, Fan Wei, et al.. Tunable operation in yttebrium-doped cladding fiber laser [J]. Acta Photonica Sinica, 1999, 28(9): 835-838.

[7] Hou Guofu, Li Yigang, Lü Kecheng, et al.. Widely tunable Yb3+-doped double-clad fiber laser [J]. Acta Photonica Sinica, 2002, 31(12): 1510-1513.

[8] Sun Hongzhi, Liang Jianzhong, Hu Yimei, et al.. A high efficient tunable Yb doped double cladding fiber laser [J]. Acta Optica Sinica, 2002, 22(11): 1372-1374.

[9] H Takebe, T Murata, K Morinaga. Compositional dependence of absorption and fluorescence of Yb3+ in oxide glasses [J]. Journal of the American Ceramic Society, 1996, 79(3): 681-687.

[10] J Kirchhof, S Unger. Codoping effects in fibers for active applications [C]. Optical Fiber Communication Conference, 1999, 2: 196-198

[11] M Weber, J Lynch, D Blackburn, et al.. Dependence of the stimulated emission cross section of Yb3+ on host glass composition [J]. IEEE J Quantum Electron, 1983, 19(10): 1600-1608.

[12] X L Zou, H Toratani. Evaluation of spectroscopic properties of Yb3+-doped glasses [J]. Phys Rev B, 1995, 52(22): 15889-15897.

[13] N T T Nguyen. The Role of Aluminum in Rare Earth-Doped Sol-Gel Silicate Glasses [D]. Hamilton College, 2007

[14] Yan Fengpin, Wang Lin, Wei Huai, et al.. Investigation of co-doping Al3+ in ytterbium-doped silica-based fiber [J]. Acta Physica Sinica, 2009, 58(3): 1793-1797.

[15] J Kirchhof, S Unger, A Schwuchow, et al.. Dopant interactions in high-power laser fibers [C]. SPIE, 2005, 5723: 261.