蓝宝石冷却叠片钕玻璃重频激光放大器

Petawatt laser with high pulse energy are required for a variety of applications, such as attosecond science, laser fusion, medicine and high-energy physics. However, petawatt laser system can only operate at single time with low efficiency. Nd:glass laser amplifier is the key unit in the petawatt laser system and is also the main reason of limiting the repetition rate improvement. For this problem, innovative sapphire cooled nd:glass laser amplifier is developed to improve the repetition rate and meet the requirement of beam quality in the pulse amplifier. By theoretical simulation of the thermal effect in sapphire/nd:glass structure with optical bonding, the impact of various parameters on the characteristics of the thermal induced wavefront aberration is analyzed. Furthermore, the multi-pass structure is optimal designed to realize the image transmission. On this basics, the seed pulse is developed with milljoule and applied to the sapphire cooled multi slabs nd:glass amplifier system, and finally realize the joule scale output at repetition rate. The sapphire cooled nd:glass amplifier can be realized in all solid state form which is with high stability and compact. Beam shaping and thermal compensation should also be expected to be realized and the repetition rate and output performance of the nd:glass laser amplifier will be greatly improved.

高能拍瓦激光在阿秒科学、激光聚变、医学、高能物理等多种领域应用广泛，但是目前拍瓦激光装置只能单次运行，效率较低。钕玻璃放大器是拍瓦激光装置中的重要单元器件，是制约重复频率提升的最主要因素之一。针对钕玻璃放大器重复频率受限的问题，提出一种利用蓝宝石对钕玻璃进行端面冷却的新方法，在提升重复频率的同时，还能满足激光放大器对光束质量的要求。通过建立叠片蓝宝石/钕玻璃光胶结构热效应理论模型，分析各参数对热波前畸变的影响；在理论指导下，优化设计多程放大腔结构，实现激光脉冲像传递传输；在此基础上，通过获得毫焦级重频种子脉冲，建立蓝宝石冷却叠片钕玻璃重频放大器系统，实现焦耳级重复频率输出。该技术方案可实现全固态化，集成性和稳定性高，并有望通过空间整形和热补偿技术实现光束质量优化，大幅度提高重频钕玻璃放大器的输出性能。

高能拍瓦激光在阿秒科学、激光聚变、医学、高能物理等多种领域应用广泛，但是目前拍瓦激光装置只能单次运行，效率较低。钕玻璃放大器是拍瓦激光装置中的重要单元器件，是制约重复频率提升的最主要因素之一。本项目提出一种利用蓝宝石对钕玻璃进行端面冷却的新方法，在提升重复频率的同时，还能满足激光放大器对光束质量的要求。项目开展的主要研究内容包括：（1）蓝宝石冷却钕玻璃热效应的理论研究；（2） 蓝宝石冷却钕玻璃激光头的特性研究，包括增益特性、热效应等；（3）LD泵浦重复频率蓝宝石冷却钕玻璃多程放大器研究；（4） 新型高效重复频率钕玻璃放大器的拓展研究，包括被动冷却INNOSLAB钕玻璃再生放大器、方形棒状钕玻璃放大器的研究。该项目培养研究生4名，发表SCI、EI论文共6篇，申请相关专利2项。