[1] Masuda H. Local fractional population measurement of the upper state 4I13/2 of an erbium-doped fiber amplifier.J Lightwave Technol, 1992,10(11):1540～1543

[3] Hofer R, Hofer M, Reider G A. High energy, sub-picosecond pulses from a Nd-doped double-clad fiber laser.Opt Commun, 1999, 169(1): 135～139

[4] Sucha G, Endert H. Femtosecond fiber lasers hit power highs.Laser Focus World, 2000, 36(8): 133～136

[5] Dominic V, MacCormack S, Waarts R, et al. 110W fibre laser.Electron Lett, 1999,35(14): 1158～1160