醇水共沉淀法制备Yb:YAG透明陶瓷及其性能研究

Yb:YAG透明陶瓷由于具有宽的吸收带和发射带、高增益、低的热负载、长的荧光寿命、高的量子效率等优点而成为有应用前景的高功率固体激光器用增益介质。本研究优化了粉体的性能并制备了高透明的Yb:YAG陶瓷。以碳酸氢铵为沉淀剂, 分别以纯水或乙醇/水混合物为溶剂, 采用共沉淀法合成了5at%Yb:YAG纳米粉体。在1250 ℃下煅烧4 h得到的所有粉体均为纯YAG相。与纯水溶剂制备的粉体相比, 醇水溶剂制备的粉体具有更小的平均晶粒尺寸和更低的团聚程度。以醇水溶剂制备的粉体为原料, 采用真空烧结法在不添加烧结助剂的情况下成功制备了5at%Yb:YAG透明陶瓷, 并对1500~1825 ℃烧结20 h和1800 ℃烧结10~50 h所得陶瓷的微观结构和直线透过率进行了探究。除在1825 ℃下烧结20 h所得的陶瓷外, 其余的5at%Yb:YAG陶瓷都具有均匀的微观结构。在1800 ℃下烧结50 h制备的5at%Yb:YAG陶瓷具有最高的光学质量, 在1100和400 nm处的直线透过率分别为78.6%和76.7%(样品厚度为2.2 mm)。该Yb:YAG透明陶瓷在937 nm处的吸收截面为5.03×10^-21 cm², 在1031 nm处的发射截面为13.48×10^-21cm²。

Fabrication and Characterizations of Yb:YAG Transparent Ceramics Using Alcohol-water Co-precipitation Method

Yb³⁺doped YAG transparent ceramics have great potential as gain medium for high-power solid-state lasers due to many advantages,such as broad absorption and emission bands,high gain,low thermal loading,long fluorescence lifetime and high quantum efficiency.So Yb:YAG transparent ceramics have gradually been paid more attention.In this work,we aimed at optimizing the properties of powders to fabricate highly transparent Yb:YAG ceramics.5at%Yb:YAG nano-powders were synthesized via the co-precipitation method by using ammonium hydrogen carbonate as the precipitant,and pure water or alcohol-water mixture as the solvent.All powders calcined at 1250℃for 4 h exhibit a pure YAG phase.Compared to the one with pure water solvent,the 5at%Yb:YAG powder synthesized with alcohol-water solvent exhibits smaller average crystallite size and lower agglomeration degree.5at%Yb:YAG transparent ceramics were successfully fabricated by vacuum sintering without sintering additives from the obtained powder with alcohol-water solvent.The microstructure and in-line transmittance of the ceramics sintered at 1500–1825℃for 20 h and 1800℃for 10–50 h were investigated.All ceramic samples show a homogeneous microstructure except for that sintered at 1825℃for 20 h.The sample sintered at 1800℃for 50 h shows the highest in-line transmittance of 78.6%at 1100 nm and 76.7%at 400 nm(2.2 mm thickness).The calculated absorption and emission cross sections are 5.03×1010^-21cm²at 937 nm and 13.48×10^–21cm²at 1031 nm,respectively.Therefore,Yb:YAG ceramics with high optical transparency and uniform microstructure have been fabricated from powder with alcohol-water solvent.