[1] [1] Masuda H, Kawai S, Aida K. Ultra-wideband hybrid amplifier comprising distributed Raman amplifier and erbium-doped fiber amplifier. Electron. Lett., 1998, 34(13):1342～1343

[2] [2] Wang J S, Vogel E M, Snitzer E. Tellurite glass: A new candidate for fiber devices. Opt. Mater., 1994, 3(4):187～203

[3] [3] Mori A, Kobayashi K, Yamada M et al.. Low noise broadband tellurite-based Er3+-doped fiber amplifiers. Electron. Lett., 1998, 34(9):887～888

[4] [4] Neindre L L, Jiang S, Hwang B C et al.. Effect of relative alkali content on absorption linewidth in erbium-doped tellurite glasses. J. Non-Cryst. Solids, 1999, 255(1):97～102

[5] [5] Sanz J, Cases R, Alcala R. Optical properties of Tm3+ in fluorozironate glass. J. Non-Cryst. Solids, 1987, 93(2,3):377～386

[6] [6] Judd B R. Optical absorption intensities of rare-earth ions. Phys. Rev., 1962, 127(3):750～761

[7] [7] Ofelt G S. Intensities of crystal spectra of rare-earth ions. J. Chem. Phys., 1962, 37(3):511～520

[8] [8] Weber M J. Selective excitation and decay of Er3+ fluorescence in LaF3. Phys. Rev., 1967, 156(2):231～241

[9] [9] Krupke W F. Optical absorption and fluorescence intensities in several rare earth-doped Y2O3 and LaF3 single crystals. Phys. Rev., 1966, 145(3):325～337

[10] [10] Wybourne B G. Spectroscopic Properties of Rare Earths. New York: Wiley, 1965. Chapter 3

[11] [11] Carnall W T et al.. Spectral intensities of the trivalent lanthanides and actinides in solution, Ⅰ. Pr3+, Nd3+, Er3+, Tm3+ and Yb3+. J. Chem. Phys., 1965, 42(11):3797～3806

[12] [12] Tanimura K, Shinn M D, Sibley W A. Optical transitions of Ho3+ ions in fluorozirconate glass. Phys. Rev. (B), 1984, 30(5):2429～2437

[13] [13] Tanable S. Optical transitions of rare earth ions for amplifiers: How the local structure works in glass. J. Non-Cryst. Solids, 1999, 259(1～3):1～9

[14] [14] Zou X, Izumitani T. Spectroscopic properties and mechanisms of excited state absorption and energy transfer upconversion for Er3+-doped glasses. J. Non-Cryst. Solids, 1993, 162(1):68～80

[16] [16] Choi Y G, Lim D S, Kim K H et al.. Enhanced 4I11/2→ 4I13/2 transition rate in Er3+/Ce3+-codoped tellurite glasses. Electron. Lett., 1999, 35(20):1765～1767

[17] [17] McCumber D E. Theory of phonon-terminated optical masers. Phys. Rev., 1964, 134(2A):A299～A306