Nd∶YAG透明陶瓷制备与激光性能

Preparation and Laser Properties of Nd∶ YAG Transparent Ceramic

采用化学沉淀法分步制备了分散性好、团聚少的纳米Y2O3、Nd2O3和Al2O3粉体,经球磨混合和喷雾干燥后,获得了颗粒形貌为球形、粒径在20-40μm间的混合陶瓷粉体。粉体经成型后,采用真空烧结工艺制备出了直径为75 mm、厚度5 mm的高透明Nd∶YAG陶瓷,其在1064 nm和400 nm处的透过率均高于80%,接近于Nd∶YAG单晶的理论透过率。应力和干涉条纹测试结果表明,所制备的Nd∶YAG透明陶瓷应力分布均匀,干涉条纹平直,具有良好的光学均匀性。FESEM和XRD测试结果表明,陶瓷的晶粒尺寸在10-20μm之间,晶界干净,没有残留气孔和杂质相。对从Nd∶YAG陶瓷圆片上选切出的3 mm×3 mm×5 mm和3 mm×3 mm×10 mm的Nd∶YAG激光陶瓷元件进行激光性能测试,实现了连续瓦级激光输出,在泵浦注入功率为18.6 W时,分别获得了7.78 W和7.75 W激光输出,光光转换效率分别为41.8%和41.7%。

The well dispersed Y2O3,Nd2O3 and Al2O3nano powders were prepared respectively through the chemical precipitation method. The nanometer oxides powders were mixed by ball milling and the mixed ceramic powders whose diameters between 20 μm and 40 μm with good spherical morphology were acquired by spray drying. By pressing and vacuum sintering process,the transparent Nd∶ YAG ceramics with the diameter of 75 mm and thickness of 5 mm were fabricated. Their transmittances at 400 nm and1064 nm were all higher than 80%,which were close to theory transmittance of Nd∶ YAG single crystal.The interference fringes and the stress test results showed that the ceramics had good optical homogeneity and lower stress with uniform distribution. The XRD patterns and FESEM images of ceramics indicate that their grain sizes were in the range of 10-20 μm,the grain boundaries were clean,and there were not any impurity phase and residual pores on the boundaries. The laser performance of 3 mm × 3 mm × 5 mm and3 mm × 3 mm × 10 mm ceramic elements that were cut from the Nd∶ YAG ceramic disk were tested and the continuous laser output was obtained by taken the laser diodes（ LD） as pump. When the input power of LD pump was 18. 6 W,the laser output power was 7. 78 W and 7. 75 W,the optical to optical conversion efficiency was 41. 8% and 41. 7% for the 3 mm × 3 mm × 5 mm and 3 mm × 3 mm × 10 mmceramic element respectively.