[2] [2] J. Nilsson, W. A. Clarkson, R. Selvas et al.. High-power wavelength-tunable cladding-pumped rare-earth-doped silica fiber lasers[J]. Optical Fiber Technology, 2004, 10(1): 5～30

[3] [3] M. Auerbach, D. Wandt, C. Fallnich et al.. High-power tunable narrow line width ytterbium-doped double-clad fiber laser[J]. Opt. Commun., 2001, 195(3): 437～441

[4] [4] J. K. Sahu, C. C. Renaud, K. Furusawa et al.. Jacketed air-clad cladding pumped ytterbium-doped fibre laser with wide tuning range[J]. Electron. Lett., 2001, 37(18): 1116～1117

[6] [6] Jes Broeng, Guillaume Vienne, Anders Petersson et al.. Air-clad photonic crystal fibers for high-power single-mode lasers[C]. Proc. SPIE, 2004, 5335: 192～201

[7] [7] W. J. Wadsworth, R. M. Percival, G. Bouwmans et al.. High power air-clad photonic crystal fibre laser[J]. Opt. Exp., 2003, 11(1): 48～53

[8] [8] www.crystalfiber.com

[11] [11] Yan Peiguang, Ruan Shuangchen, Lin Haojia et al.. Supercontinuum generation in a photonic crystal fibre[J]. Chin. Phys. Lett., 2004, 21(6): 1093~1095