晶化对Nd^(3+)∶NaYF_4荧光动力学的影响

Fluorescent Dynamics Effects of Crystallization on Nd^(3+)∶NaYF_4

采用融熔急冷法制备了前驱玻璃和与之晶化后的纳米晶结构玻璃陶瓷。利用光辐射理论,计算在两种样品中Nd^(3+)各能级的辐射跃迁几率。根据Dexter理论,得到交叉弛豫几率与Nd^(3+)相对浓度的关系。基于速率方程,描述荧光动力学过程。结果表明:晶化作用能降低Nd^(3+)各能级辐射跃迁几率,减小交叉弛豫几率,延缓动态系统趋于平衡的速率。同时,在较低Nd^(3+)相对浓度掺杂时,晶化作用提高~4F_(3/2)能级的相对粒子数,减少~4I_(9/2)能级的相对粒子数,结果显示晶化作用能有效提高1.06μm的输出。

Nd^3＋：NaYF4 precursor glass and a corresponding nano-structured glass ceramic were prepared by melt-quenching process. Radiative transition probabilities were calculated by optical radiation theory. The relationship between cross relaxation probability and Nd^3＋ relative concentration was shown by Dexter theory. Fluorescent kinetic process had been proposed, and a model was built using rate equations. The results suggest that the crystallization can increase radiative lifetime of every energy level, reduce the cross relaxation probability and delayed the dynamic system tending to the steady state. Meanwhile, the crystallization has improved the relative population of ^4F3/2 energy level and lower the relative population of ^4I9/2 energy level when the lower Nd^3＋ relative doping concentration. So, crystallization effect can effectively increase the 1.06 μm output.