Gorni G, Velázquez Jose J, Kochanowicz M, Dorosz D, Balda R, Fernández J, Durán A, Pascual M J
Ceramics and Glass Institute, CSIC Madrid Spain
FunGlass-Centre for Functional and Surface Functionalized Glass, Alexander Dubček University of Trenčín Trenčín Slovakia.
RSC Adv. 2019 Oct 8;9(54):31699-31707. doi: 10.1039/c9ra05182a. eCollection 2019 Oct 1.
Novel glass-ceramic optical fibers containing NaLuF nanocrystals doped with 0.5ErF and 2YbF (mol%) have been prepared by the rod-in-tube method and controlled crystallization. NaLuF nanocrystals with a size around 20 nm are obtained after heat treatment at 600 °C. Intense upconverted green and red emissions due to (H, S) → I and F → I transitions, respectively, together with a blue emission due to H → I transition have been observed under excitation at 980 nm. The intensity of the green and red upconversion bands shows a nearly linear dependence on the excitation power which can be explained by saturation effects in the intermediate energy states and proves that a sensitized energy transfer upconversion process is responsible for the population of the emitting levels of Er ions. The upconversion emission color changes from yellow to green by increasing the excitation power density which allows to manipulate the color output of the Er emission in the glass-ceramic fibers. The tunable emission color is easily detected with the naked eye. This interesting characteristic makes these glass-ceramic fibers promising materials for photonic applications.
采用管中棒法和控制晶化法制备了新型玻璃陶瓷光纤，其包含掺杂有0.5%（摩尔分数）ErF₃和2%（摩尔分数）YbF₃的NaLuF₄纳米晶体。在600℃热处理后获得了尺寸约为20nm的NaLuF₄纳米晶体。在980nm激发下，分别观察到了由于（H，S）→I和F→I跃迁产生的强烈上转换绿色和红色发射，以及由于H→I跃迁产生的蓝色发射。绿色和红色上转换带的强度对激发功率呈现近似线性依赖关系，这可以通过中间能级的饱和效应来解释，并且证明了敏化能量转移上转换过程是导致Er离子发射能级粒子数增加的原因。通过增加激发功率密度，上转换发射颜色从黄色变为绿色，这使得能够操控玻璃陶瓷光纤中Er发射的颜色输出。可调谐发射颜色用肉眼很容易检测到。这一有趣特性使得这些玻璃陶瓷光纤成为光子应用中有前景的材料。
