神光Ⅱ升级装置波前传输计算模型与验证

Wavefront Propagation Modeling and Verification of the SG-Ⅱ Updated Laser Facility

基于衍射理论和神光Ⅱ升级激光装置的光路结构及光学元件波前像差,建立了激光装置光束波前像差传输计算模型,用以获取在实验中难以取得,但对激光系统设计和安全运行非常重要的变形镜校正面型、放大器动态波前像差、空间滤波器波前像差和焦斑形态等过程数据。利用该模型对激光装置常规运行时的静态传输、变形镜加压静态传输和大能量发射3种状态下的波前传输进行理论分析,计算结果与实验测量相一致,并在此基础上对变形镜未加压大能量发射波前传输进行计算。计算模型可用于指导相关器件的设计,优化激光运行控制模式,有利于提高激光装置输出波前质量。

Based on the diffraction theory, the specific beam structure and optics wavefront data of the SG-II updated laser facility, a calculation model of the wavefront propagation for the facility is established. Using the calculation model some important data for design and operation of the facility are gained, including the corrected profile of deformed mirror, dynamic wavefront aberration of the amplifier, wavefront aberration and focus of the spatial filter, which are difficult to get by experiment. Analysis and comparison under three types of conventional operation, such as static propagation, static propagation and large energy shot with adaptive wavefront correction, indicates that the theoretical results are in good agreement with the experimental data. And the wavefront propagation of large energy shot in absence of the adaptive wavefront correction is calculated. The wavefront propagation model can be used to improve design of the related devices, optimize operation and control mode of the laser facility, and improve wavefront quality of the output laser beam.