Abstract Tm3+, Yb3+: CdF2 single crystals with good optical quality are grown by the standard Bridgman method. The crystal structure is checked by means of X-ray diffraction analysis. Under 800 nm excitation of Tm3+ ions, the samples show an intense infrared band around 1800 nm associated with the 3F4→3H6 transition. The sample exhibit also upconverted luminescence under 975 nm laser excitation which is a signature of an efficient energy transfer between Yb3+ and Tm3+ ions. The pump power dependence of all upconversion intensities have been analyzed in accordance with a proposed upconversion mechanism. The temporal evolution curves of the upconversion emissions obtained for the lowest Tm3+ concentration sample gives longer decays and as result the highest emission upconversion intensities.

中文翻译：

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Tm3+-Yb3+共掺杂CdF2单晶的近红外和上转换发光

摘要 Tm3+、Yb3+：采用标准Bridgman 法生长出具有良好光学质量的CdF2 单晶。通过X射线衍射分析检查晶体结构。在 Tm3+ 离子的 800 nm 激发下，样品显示出与 3F4→3H6 跃迁相关的 1800 nm 附近的强红外波段。该样品在 975 nm 激光激发下也表现出上转换发光，这是 Yb3+ 和 Tm3+ 离子之间有效能量转移的标志。已经根据提出的上转换机制分析了所有上转换强度的泵浦功率依赖性。对于最低 Tm3+ 浓度样品获得的上转换排放的时间演变曲线给出了更长的衰减，因此具有最高的排放上转换强度。