大口径N41型激光钕玻璃的小信号增益

Small signal gain of glass N41in large aperture Nd:laser

比较了国内外高功率激光钕玻璃的主要性质及发展状态,重点分析了中国科学院上海光学精密机械研究所近年来研制的大口径N41型激光钕玻璃的物理性能及其在400mm口径片状放大器系统中的增益特性。利用优化片状放大器技术方案,测定了N41钕玻璃与N31~42钕玻璃的小信号净增益系数和大口径增益均匀性。实验显示,在相同测试条件下,N41型钕玻璃的某些关键性能参数优于N31型钕玻璃;在相同抽运条件下,N41钕玻璃和N31钕玻璃的平均小信号净增益系数分别达到5.3%和5.16%,远优于神光-Ⅲ主机N31~35钕玻璃的在线测试结果;385mm口径内N41钕玻璃增益均匀性为1.085∶1,N41钕玻璃的包边性能满足装置使用要求。结果表明：新型N41钕玻璃的增益性能较N31钕玻璃有了显著提升,在放大器结构优化的条件下,可满足下一代ICF激光驱动系统的需求。

The main properties of high-power Nd ~ laser glass in China and abroad and its development situations were compared. Then, the physical properties of large aperture N41 Nd ＇ glass developed by Shanghai Institute of Optics and Fine Mechanics of the Chinese Academy of Sciences（SIOM） were analyzed and its gain characteristics in a segment amplification system with an aperture of 400 nm was investigated. An optimized technological scheme was used to measure the small-signal net-gain param-eters of N41 glass and N31--42 glass and the gain homogeneity of large aperture glass under the same condition. The results indicate that the several key parameters of N41 glass are better than that of the N31 glass. Under the same pumping condition, the average small-signal net-gain parameters for N41 glass and N31 glass are 5.3% and 5.16%, respectively, much better than the online experimental re- sult of N31--35 glass used in Shenguang-Ⅲ. Moreover, the gain homogeneity of N41 glass with an aperture of 385 mm is 1. 085 ： 1, and its cladding glass meets the requirement of Shenguang-Ⅲ. It concludes that the gain characteristics of the N41 glass have been improved greatly as compared with that of the N31 glass. When the amplifier structure is optimized, the N41 glass can be used in the Shenguang system in the future.