Opt Lett. 2015 Aug 1;40(15):3580-3. doi: 10.1364/OL.40.003580.
We demonstrate a versatile approach to fine-tuning the ratio of blue to near-infrared emission intensity from Tm3+ ions in LaF3 nanocrystals by adjusting the pulse widths and excitation wavelengths of red laser beams. The mechanism of color-tunable Tm3+ emission by pulse widths is explored, and a mechanism based on promoting the population of some luminescence levels and cutting off the population of others by suitably adjusting pulse duration is proposed. The underlying reason of excitation wavelength-modulated emission is ascribed to tuning absorption probability ratio of ground state absorption to excited state absorption by tuning the matching degree between the energies of excitation wavelength and ground (excited) state absorption of Tm3+. The ability of our LaF3:Tm3+ nanocrystals to emit variable emissions on demand in response to pulse width and excitation wavelength provides keen insights into controlling the population processes of luminescent levels and offers a versatile approach for tuning the spectral output.
我们展示了一种灵活的方法，可以通过调整红色激光束的脉冲宽度和激发波长来微调 LaF3 纳米晶体中 Tm3+离子的蓝到近红外发射强度比。我们探讨了通过脉冲宽度实现可调谐 Tm3+发射的机制，并提出了一种基于适当调整脉冲持续时间来促进某些发光能级的粒子数增加和截断其他能级的粒子数的机制。通过调整激发波长与 Tm3+的基态吸收和激发态吸收之间的能量匹配程度来调节基态吸收与激发态吸收的吸收概率比，从而解释了激发波长调制发射的基本原理。我们的 LaF3:Tm3+纳米晶体能够根据脉冲宽度和激发波长的要求发出可变的发射，这为控制发光能级的粒子数过程提供了深刻的见解，并为光谱输出的调谐提供了一种通用的方法。
