可有效实现3μm中红外波段激光输出的稀土掺杂LiYF4单晶体研究

Laser at 3μm mid-infrared wavelength has a very important applications in civilian and military. This project aims to develop key techniques of a Bridgman method that is used to produce large size and high quality rare earth ions doped LiYF4 single crystal of highly efficient output of 3μm mid-infrared wavelength laser on one hand, and on the other ascertain the mechanism of enhanced intensity for emission at 3μm mid-infrared wavelength. The Er3+ ion will be taken as main researching luminous center, and the emission with high efficiency of Er3+ ion from 4I11/2 to 4I13/2 transition will be realized by introducing Nd3+,Pr3+,Tm3+, et al. into crystal as sensitizers. We intend to study the growth parameters of the rare earth doped YLiF4 single crystals, optical spectra of 3μm mid-infrared wavelength,ideal doping concentration and doping rare earths. Enhancing the performance of 3μm laser emission will be realized in terms of identifying the mechanisms and affecting factors for Er3+ ion florescence will be identified from their optical spectra.The laser rod of rare earth doped LiYF4 crystal will be processed from the obtained LiYF4 crystal. The performance of 3μm laser output of the rod will be investigated and analysized. It is proposed that the rare earth ions doped LiYF4 single crystals possess comprehensive performance in thermal stability, chemistry-physics, mechanical strength, optcal transmission, and 3μm emission, and the performance of high-proficiency 3μm laser output will be realized. Finally, this project will provide a technology foundation to the research and productization of the mid-infrared materials and devices in the future.

3微米中红外激光在民用及军用领域具有重要的应用。本项目以获得一种可高效实现3微米激光输出的稀土离子掺杂优质大尺寸氟化钇锂单晶的坩锅下降法关键制备技术与增强中红外发光机理研究为目标。以Er3+为主要研究的中心发光离子，通过Nd3+、Pr3+、Tm3+等稀土离子的敏化作用，实现4I11/2→4I13/2能级跃起的中红外高效发光。研究稀土掺杂LiYF4晶体的坩锅下降法生长条件及晶体的中红外发光特性及理想掺杂浓度与种类。通过光谱特性研究3μm产生的发光机理及其影响因素，实现增强3μm光谱性能的优化。以此晶体为材料，加工成激光棒，并对激光棒的中红外激光输出特性进行深入分析。稀土离子掺杂的LiYF4晶体可望具备热学、物化、机械强度、光学透过及中红外发光等综合性能优良的特性，有望获得高效的3μm激光输出。本项目研究工作对探索我国新型中红外激光晶体材料具有重要意义，为今后在中红外激光材料与器件的研制及产

3 微米中红外激光在民用及军用领域具有重要的应用。本项目开展了一种可高效实现3 微米激光输出的稀土离子掺杂优质大尺寸氟化钇锂单晶的坩锅下降法关键制备技术与增强中红外发光机理研究。以Er3+离子为主要研究的中心发光离子，通过Nd3+、Pr3+、Tm3+等稀土离子的敏化作用，实现了Er3+离子中4I11/2→4I13/2 能级跃起的中红外高效发光。着重研究了多种稀土离子掺杂LiYF4 晶体的坩锅下降法生长条件以及晶体的中红外发光特性与稀土离子的掺杂浓度与种类的关系。通过光谱特性研究产生2.7μm 波段的发光机理及其影响因素。阐明了Nd3+、Pr3+、Tm3+等与Er3+离子的能量传递与作用机理。以Er3+,Nd3+掺杂LiYF4晶体为基础加工成尺寸为8×5×2mm3的激光棒进行激光实验。在连续792nmLD激光器泵浦下，实现了2.75μm激光输出。这些成果为今后在全固化中红外光纤激光器的研制及产业化等方面奠定一定的技术基础。