中文摘要：

采用溶胶-凝胶（Sol—gel）法制备1mol％Tm^3＋、1mol％Tm^3＋和10mol％Yb^3＋共掺杂Y2Ti2O7粉末。Tm^3＋掺杂Y2Ti2O7为Y2Ti2O7相和微量TiO2相的混合结构，Yb^3＋共掺杂不改变Tm^3＋掺杂Y2Ti2O7相结构。在976nm半导体激光器（LD）激发下，在430～500nm和620—750nm波长范围内获得了蓝色和红外上转换发光，分别对应于Tm^3＋的^1G4→^3H6和^3H4→^3H6跃迁。Yb^3＋共掺杂显著提高了Tm^3＋掺杂Y2Ti2O7的上转换发光强度。研究表明：随着LD激发电压增大，Tm^3＋-Yb^3＋共掺杂Y2Ti2O7上转换发光强度逐渐增大，且上转换发光强度随LD激发功率增大呈现两阶段变化规律；随着温度升高，Tm^3＋-Yb^3＋共掺杂Y2Ti2O7上转换发光强度逐渐降低，这是由无辐射弛豫速率随着温度升高而增加所致。

英文摘要：

The 1 mol% Tin^3＋, 1 mol% Tm^3＋ and 10 tool% Yb^3＋ co -doped Y2Ti2O7 powders were prepared by sol- gel method. The Tm^3＋ doped Y2Ti2O7 was composed of mixture of Y2Ti2O7 and tiny TiO2 phases. Yb^3＋ co - doping had no effect on the phase structure of Tm^3＋ doped Y2Ti2O7. The blue and infrared up -conversion emissions in the wavelength range of 430 - 500 nm and 620 - 750 nm were detected by a 980 - nm semiconductor laser diode （LD） excitation, which corresponding to the ^1G4→^3H6 and ^3H4→^3H6 transitions of Tm^3＋. The up -conversion emissions intensity of Tm^3＋ doped Y2Ti2O7 powders was enhanced by Yb^3＋ co -doping. The up -conversion emissions intensity of Tm^3＋ -Yb^3＋ co -doped Y2Ti2O7 increased gradually with increasing the excitation voltage of LD. The two step process was observed for the up - conversion emission intensity with increasing the excitation power of LD. The up - conversion emissions intensity of Tm^3＋ -Yb^3＋ co- doped Y2Ti2O7 was decreased with increasing the temperature, which caused by the increase of rate of nonradiative relaxation rate with temperature.