[1] Zhang Long, Zhang Junjie, Qi Changhong et al.. Energy transfer and upconversion in Tm3+-Yb3+ co-doped AlF3-based fluoride glass［J］. Chinese J. Lasers, 2000, A27(5): 459～465

[2] Li Chenxia, Kang Juan, Zheng Fei et al.. Upconversion luminescence of Ho3+/Yb3+ codoped oxyfluoride silicate glass ceramics［J］. Chinese J. Lasers, 2009, 36(5): 1184～1189

[3] Li Chenxia, Xu Shiqing, Ye Renguang et al.. Optical properties of Eu2+/Eu3+ doped SiO2-Al2O3-ZnO-K2CO3 Glass-Ceramic［J］. Acta Optica Sinica, 2010, 30(4): 1084～1087

[4] Y. Hizhnyi, A. Oliynyk, O. Gomenyuk et al.. Electronic structure and optical properties of Ti-doped phosphate crystals［J］. Materials Science and Engineering: B, 2007, 144(1-3): 7～10

[5] X. Meng, K. Tanaka, Intense greenish emission from d0 transition metal ion Ti4+ in oxide glass［J］. Appl. Phys. Lett., 2007, 90: 051917-1～3

[6] A. Sennaroglu. Broadly tunable Cr4+-doped solid-state lasers in the near infrared and visible［J］. Prog. Quantum Electron., 2002, 26(6): 287～352

[7] L. H. C. Andrade, S. M. Lima, Long fluorescence lifetime of Ti3+-doped low silica calcium aluminosilicate glass［J］. Phys. Rev. Lett., 2008, 100(2): 027402-1～027402-4

[8] T. Sato, M. Shirai, K. Tanaka et al.. Strong blue emission from Ti-doped MgAl2O4 crystals［J］. J. Lumin., 2005, 114(2): 155～161

[9] T. Sekiya, M. Tasaki, K. Wakabayashi et al.. Relaxation process in anatase TiO2 single crystals with different colors［J］. J. Lumin., 2004, 108(1-4): 69～73

[10] N. M. Avram, M. G. Brik, C. N. Avram et al.. Energy levels of transition metal ions in laser Crystals: Crystal field analysis and electron-phonon interaction［J］. Rom. Journ. Phys., 2006, 51(1-2): 151～175

[11] M. Kumar, A. Uniyal, A. P. S. Chauhan et al.. Optical absorption and fluorescent behaviour of titanium ions in silicate glasses［J］. Bull. Mater. Sci., 2003, 26(3): 335～341

[12] U. Hmmerich, Y. Shen, K. Bray. High-pressure luminescence studies of Cr4+-doped laser materials［J］. J. Lumin., 1997, 72-74: 139～140

[13] N. B. Angert, N. I. Borodin, V. M. Garmash et al.. Lasing due to impurity color centers in yttrium aluminum garnet Crystals at wavelengths in the range 1.35～1.45 μm［J］. Sov. J. Quantum. Electron., 1988, 18(1): 73～74

[14] W. Jia, H. Liu, S. Jaffe et al.. Spectroscopy of Cr3+ and Cr4+ ions in forterite［J］. Phys. Rev. B, 1991, 43(7): 5234～5242

[15] Chen Wenxin, Zhang Jingxian, Yi Shoujun et al.. Blue-purple long afterlow luminesence property of Zn2SiO4Ga [J]. J. Jinan University, 2004, 25(3): 322～330