中文摘要：

采用固相反应方法,制备了Er2O3浓度固定为0.5mol%,Yb2O3浓度范围为0.0mol%—5.5mol%的Er/Yb共掺激光玻璃.通过吸收光谱、光致荧光光谱和上转换荧光光谱,研究了Yb2O3浓度对Er^3＋荧光特性的影响,并探讨了相关的物理机制.研究结果表明：Yb^3＋共掺对Er^3＋的^4I13/2吸收截面的影响存在一个临界浓度.当Yb^3＋浓度超过此临界浓度时,吸收截面面积随Yb2O3浓度的增加而线性增加,从而导致Er^3＋的^4I13/2→^4I15/2辐射跃迁过程的增强.Yb^3＋掺杂显著提高了Er^3＋的荧光强度,并导致荧光光谱的明显宽化.定量分析表明,受主到施主的反向能量传递随Yb2O3浓度的增加而逐渐增加,但不是导致Er^3＋的^4I13/2→^4I15/2跃迁过程中荧光强度饱和的主要原因.而Yb^3＋掺杂所引起的荧光量子效率降低和抽运过程中存在的激发态粒子数本征饱和才是荧光强度饱和甚至降低的根本原因.Yb^3＋共掺杂引起的敏化作用而导致的Yb^3＋的^2F5/2能级和Er^3＋的^4I11/2能级粒子数密度增加,促进了Yb^3＋,Er^3＋之间合作上转换的增强.这是上转换荧光增强的主要贡献.

英文摘要：

Er/Yb co-doped borate-silicate glass with 0.5mol% Er2O3 were fabricated by solid reaction. The concentration of Yb2O3 was in the range of 0. 0mol% to 5.5mol% . The spectra of absorption, photoluminescence （PL） and up-conversion luminescence were analyzed. A critical value is found in the dependence of PL and absorption on the concentration of Yb2O3 . When the concentration of Yb2O3 is greater than the critical value, the area of the absorption cress-section of Er^3＋ ions near 1535 nm has a linear increase with the increase of Yb2O3 concentration. Yb^3＋ co-doping makes the PL intensity to enhance and the PL spectra of Er^3＋ ions to broaden considerably. Quantitative analysis indicates that the inverse transfer energy from the acceptor to the donor does increase with the increase of Yb2O3 concentration. However, it could not be the dominaing factor causing the saturation of PL intensity. We ascribe the saturation of PL intensity to be due to the decrease of PL quantum efficiency and the saturation of excited states in the system caused by the increase of sensitizers. The sensitization of Yb^3＋ ions also results in the increase of Yb^3＋ -^2F5/2 and Er^3＋ -^4I11/2 populations, which promotes the cooperative up-conversion between Er^3＋ and Yb^3＋ ions.