介绍了中国科学院上海光学精密机械研究所开展的激光钕玻璃连续熔炼技术, 描述了该项技术近年来的研究进展和研究成果。给出了N31激光钕玻璃的连续熔炼流程, 介绍了开展的磷酸盐钕玻璃连续熔炼单元技术的模拟, 连续熔炼实验线的设计、建设、改造和验证等大量工作。成功完成了除羟基、除铂颗粒、过渡金属杂质离子控制、大尺寸成型和低应力隧道窑退火等一系列关键单元技术, 实现了N31钕玻璃的连续熔炼批量制造。实验显示: 连续熔炼N31激光钕玻璃的荧光寿命、激光波长吸收损耗、光学均匀性等指标达到了神光装置的使用要求。比较结果显示: 连续熔炼钕玻璃的参数一致性和400 nm吸收系数指标均优于坩埚熔炼的激光玻璃; 而它的3 333 nm吸收系数和铂颗粒破坏阈值优于美国劳伦斯利弗莫尔国家实验室报道的连续熔炼LHG-8钕玻璃。

This paper focuses on the continuous melting technology of neodymium laser glass carried out by Shanghai Institute of Optics and Fine Mechanics of the Chinese Academy of Sciences since 2005. It describes the research progress and some achievements of the technology. The continuous melting processing of N31 laser Nd glass is given, continuous melting of phosphate glass is simulated and a lots of experiments on the design, establishment, improvement and verification of the continuous melting line are carried out. A series of key technologies of continuous melting such as hydroxylation removal, Pt-inclusion removal, and transition metal impurity control, large size casting and birefringence control in lehr annealing are solved and the mass production of N31 laser glass is realized. The experimental achievements show that the fluorescent lifetime, laser attenuation at 1 053 nm, optical homogeneity and other properties of the continuous melted laser glass meet the requirements of the Shenguang facility. The comparison experiments show that the optical parameter homogeneity and absorption coefficient at 400 nm of the continuous melted laser glass are superior to those of the pot melted glass. Moreover, the absorption coefficient at 3 333 nm and larger laser damage threshold caused by platinum inclusion of the N31 laser glass are better than those of LHG-8 glass used in Lawrence Livermore National Laboratory in the United States.