[1] [1] Elizabeth Downing, Lambertus Hesselink, John Ralston et al.. A three-color, solid-state, three-dimensional display ［J］. Science, 1996, 273(5279): 1185～1189

[2] [2] Hai Lin, Gerald Meredith, Shibin Jiang et al.. Optical transitions and visible upconversion in Er3+ doped niobic tellurite glass ［J］. J. Appl. Phys., 2003, 93(1): 186～191

[3] [3] Can T. Xu, Niclas Svensson, Johan Axelsson et al.. Autofluorescence insensitive imaging using upconverting nanocrystals in scattering media ［J］. Appl. Phys. Lett., 2008, 93(17): 171103

[4] [4] Daisuke Matsuura. Red, green, and blue upconversion luminescence of trivalent-rare-earth ion-doped Y2O3 nanocrystals ［J］. Appl. Phys. Lett., 2002, 81(24): 4526～4528

[5] [5] Cao Baosheng, Feng Zhiqing, He Yangyang et al.. Effect of Li+ codoping on the upconversion emissions of Er3+-doped TiO2［J］. Acta Optica Sinica, 2010, 30(7): 1861～1865

[6] [6] Dong Xiangting, Gao Xubo, Wang Jinxian et al.. Fabrication and characterization of Er3+, Yb3+Y3Al5O12 upconversion luminescent nanofibers［J］. Acta Optica Sinica, 2010, 30(7): 1883～1890

[7] [7] Zhang Zhenzhong, Zhang Jihong, Hu Qi et al.. Structure and up-conversion luminescence properties in Er3+-doped TiO2 nanocrystals［J］. Acta Optica Sinica, 2009, 29(s1): 172～176

[8] [8] Amitava Patra, Christopher S. Friend, Rakesh Kapoor et al.. Effect of crystal nature on upconversion luminescence in Er3+ZrO2 nanocrystals ［J］. Appl. Phys. Lett., 2003, 83(2): 284～286

[9] [9] Rakesh Kapoor, Christopher S. Friend, Abani Biswas et al.. Highly efficient infrared-to-visible energy upconversion in Er3+Y2O3［J］. Opt. Lett., 2000, 25(5): 338～340

[10] [10] Fiorenzo Vetrone, J. Christopher Boyer, John A. Capobianco et al.. Effect of Yb3+ codoping on the upconversion emission in nanocrystalline Y2O3Er3+ ［J］. J. Phys. Chem. B, 2003, 107(5): 1107～1112

[11] [11] Huijuan Liang, Yangdong Zheng, Guanying Chen et al.. Enhancement of upconversion luminescence of Y2O3Er3+ nanocrystals by codoping Li+-Zn2+ ［J］. J. Alloys Compd., 2011, 509(2): 409～413

[12] [12] Z. Zhou, T. Komori, T. Ayukawa et al.. Li- and Er-codoped ZnO with enhanced 1.54 μm photoemission ［J］. Appl. Phys. Lett., 2005, 87(9): 091109

[13] [13] Y. F. Bai, K. Yang, Y. X. Wang et al.. Enhancement of the upconversion photoluminescence intensity in Li+ and Er3+ codoped Y2O3 nanocrystals ［J］. Opt. Commun., 2008, 281(10): 2930～2932

[14] [14] J. Zhang, S. Wang, T. Rong et al.. Upconversion luminescence in Er3+ doped and Yb3+/Er3+ codoped yttria nanocrystalline powders ［J］. J. Am. Ceram. Soc., 2004, 87(6): 1072～1075

[15] [15] J. A. Capobianco, F. Vetrone, J. C. Boyer et al.. Enhancement of red emission (4F9/2→ 4I15/2) via upconversion in bulk and nanocrystalline cubic Y2O3Er3+ ［J］. J. Phys. Chem. B, 2002, 106(6): 1181～1187

[16] [16] T. T. Van, J. P. Chang. Controlled erbium incorporation and photoluminescence of Er-doped Y2O3 ［J］. Appl. Phys. Lett., 2005, 87(1): 011907

[17] [17] L. Sun, C. Qian, C. Liao et al.. Luminescent properties of Li+ doped nanosized Y2O3:Eu ［J］. Solid State Commun., 2001, 119(6): 393～396