[1] Oliveira A S, Araujo M T, Gouveia A S et al.. Upconversion fluorescence spectroscopy of Er3+/Yb3+ doped heavy metal Bi2O3-Na2O-Nb2O5-GeO2 glass. J. Appl. Phys., 1998, 83(1):604～606
[2] Huang L H, Liu X R, Xu W et al.. Infrared and visible luminescence properties of Er3+ and Yb3+ ions codoped Ca3Al2Ge3O12 glass under 978 nm diode laser excitation. J. Appl. Phys., 2001, 90(11): 5550～5553
[3] Wang Y, Ohwaki. High-efficiency infrared to visible upconversion of Er3+ in BaCl2. J. Appl. Phys., 1993, 74(2): 1272～1278
[4] Pan Z, Morgan S H, Loper A et al.. Infrared to visible upconversion in Er3+ doped lead germanate glass: effects of Er3+ ion concentration. J. Appl. Phys., 1995, 77(9): 4688～4692
[5] France M. Photon avalanche upconversion in rare earth laser materials. Opt. Mater., 1999, 11:181～203
[6] Lin H, Meredith G, Jiang S B et al.. Optical transitions and visible upconversion in Er3+ doped niobic tellurite glass. J. Appl. Phys., 2003, 93(1): 186～191
[7] Soga K, Inoue H, Makishima A. Calculation and simulation of spectroscopic properties for rare earth ions in chloro-fluorozirconate glasses. J. Non-Crys. Solids, 2000, 274: 69～74
[8] Lin H, Pun E Y B, Liu X R. Er3+-doped Na2O Cd3Al2Si3O12 glass for infrared and upconversion applications. J. Non-Crys. Solids, 2001, 283(1): 27～33
[9] Higuchi H, Takahashi M, Kawamoto Y. Optical transitions and frequency upconversion emission of Er3+ ions in Ga2S3-GeS2-La2S3 glasses. J. Appl. Phys., 1998, 83(1): 19～27
[10] Tsuda M, Soga K, Inoue H. Upconversion mechanism in Er3+-doped fluorozirconate glasses under 800 nm excitation. J. Appl. Phys., 1999, 85(1): 29～37
[11] Snoeks E, Hoven G N, Polman A. Optimization of an Er-doped silica glass optical waveguide amplifier. IEEE J. Quant. Electron., 1996, 32: 1680～1684
[13] Petit L, Cardinal T, Videau J J. Effect of the introduction of Na2B4O7 on erbium luminescence in tellurite glasses. J. Non-Crystalline Solids, 2002, 298(1): 76～88
