高功率激光装置基于靶点的同步测量技术  

High Power Laser Synchronous Measurement Technology at the Target

作　　者：张天宇 范薇[1,2,3] 汪小超 杨琳[1,3] 华能[1] 李国扬 姜秀青[1] 郭亚晶[1] 张攀政[1,2,3] 谢志勇[1,4] 孙明营 张生佳[1] 汪涛[1] 宋佳驹 顾侃[1] Zhang Tianyu;Fan Wei;Wang Xiaochao;Yang Lin;Hua Neng;Li Guoyang;Jiang Xiuqing;Guo Yajing;Zhang Panzheng;Xie Zhiyong;Sun Mingying;Zhang Shengjia;Wang Tao;Song Jiaju;Gu Kan(Key Laboratory of High Power Laser and Physics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China;Collaborative Innovation Center of IFSA,Shanghai Jiao Tong University,Shanghai 200240,China;Shanghai Institute of Laser Plasma,China Academy of Engineering Physics,Shanghai 201800,China)

机构地区：[1]中国科学院上海光学精密机械研究所高功率激光物理联合实验室,上海201800 [2]中国科学院大学材料科学与光电研究中心,北京100049 [3]上海交通大学IFSA协同创新中心,上海200240 [4]中国工程物理研究院上海激光等离子体研究所,上海201800

出　　处：《中国激光》2024年第13期143-152,共10页Chinese Journal of Lasers

基　　金：中国科学院战略性先导科技专项(XDA25020303)。

摘　　要：针对惯性约束聚变高功率激光装置对多路激光到达靶点的高精度时间同步调控需求,提出一种基于散射球的靶球同位替代的同步测量技术,该技术可有效避免由于测试点偏离靶心带来的同步测试误差。利用放置于靶场中心的散射球,将来自任一方向入射的单束紫外光近各向同性地散射到4π立体角内。采用非球面透镜结合高速光电探测技术捕获散射光,从而测得待测光束与时间参考基准的同步时间延迟。在神光II装置上开展了在线验证实验,获得基于靶点的长脉冲时间同步抖动小于1.5 ps的延时的测试结果。并离线验证了基于散射球的技术方案应用于10 ps脉宽激光束之间的同步测试可行性。该方法可为高功率激光装置长长、长短脉冲之间和皮秒激光之间的皮秒级高精度时间同步测试提供技术支持。Objective Laser inertial confinement fusion(ICF) achieves controllable nuclear fusion to produce clean and safe energy. The ICF experiment has stringent energy, power balance, and waveform consistency requirements for pulses arriving at the target point.Uniform driving of the target surface requires accurate beam synchronization to achieve an accurate power balance. Therefore,synchronous measurement and adjustment technology for multibeam lasers is critical.Methods To achieve synchronous measurements of multiple beams at the target point, the testing method and principle employed are shown in Fig. 4. The seed light was sampled and coupled as the reference light after passing through the regenerator and then connected to a 1053 nm single-mode fiber with a length of approximately 130 m. After transmission through the fiber, it was converted into an electrical signal using a photodiode and entered an oscilloscope. The central target sphere in the target chamber is replaced by an ~800 μm diameter alumina scattering sphere positioned at the center of the target chamber using the target positioning system. In this experiment, a single beam of ultraviolet light from any direction is scattered isotropically at a solid angle of 4π, covering the entire target chamber. A fused quartz nonspherical mirror was placed on a flange in the direction of non-transmitting light to capture the scattered light. The scattered light is detected using a fast photomultiplier tube and converted into an electrical signal, which is input into another oscilloscope channel. The synchronization time delay between the measured beam and the time reference can be measured.Results and Discussions The time delay between the first signal light and the infrared reference light of the Shenguang-II device is measured. Fig. 6 shows the track data obtained using an oscilloscope. The blue curve represents the infrared reference light, and the red curve represents the ultraviolet signal light. The infrared reference and ultraviolet signals are fitted with

关 键 词：同步测量 靶点 散射球 抖动 

分 类 号：TN247[电子电信—物理电子学]