In this work, luminescence processes in polycrystalline NaLaF₄:Tm³⁺ and NaLaF₄:Tm³⁺,Yb³⁺ materials were studied. Luminescence spectra and decay kinetics measurements were performed for NaLaF₄ doped with various Tm³⁺ concentrations (0.01, 0.1, 0.5, 1, and 2 mol%) under direct excitation to ³P₀, ¹D₂, ¹G₄, and ³H₄ states. It was found that some of the Tm³⁺ excited states are more affected by Tm³⁺ concentration than other states. Under infrared excitation of Yb³⁺, energy transfer to Tm³⁺ occurred and intensive ultraviolet and blue up-conversion luminescence was observed. Possible up-conversion mechanisms are discussed. Spectroscopic measurements show that long-duration excitation radiation reduces ultraviolet up-conversion luminescence intensity, and this intensity reduction is related to sample heating due to high excitation radiation density and a poor heat sink from samples. It was found that sample configuration for spectroscopic measurements is crucial to correctly describe measured up-conversion luminescence spectra.

在这项工作中，研究了多晶NaLaF ₄ :Tm ³⁺和NaLaF ₄ :Tm ³⁺ ,Yb ³⁺材料的发光过程。^{在直接激发到3} P ₀、¹ D ₂、¹ G ₄和³下，对掺杂有各种 Tm ³⁺浓度（0.01、0.1、0.5、1 和 2 mol%）的 NaLaF ₄进行发光光谱和衰减动力学测量H ₄状态。发现一些Tm ³⁺激发态受Tm ^{3+影响更大}浓度高于其他州。在Yb ^{3+的红外激发下，发生了向Tm 3+}的能量转移，并观察到强烈的紫外和蓝色上转换发光。讨论了可能的上转换机制。光谱测量表明，长时间的激发辐射降低了紫外上转换发光强度，这种强度降低与样品加热有关，原因是激发辐射密度高，样品散热不良。发现光谱测量的样品配置对于正确描述测量的上转换发光光谱至关重要。