Irradiation Uniformity by Combining Smoothing by Spectral Dispersion and Lens Array

为满足激光惯性约束聚变中靶面激光辐照不均匀性低于5%的要求, 在目前使用透镜列阵基础上, 提出了谱色散平滑与透镜列阵联用方案, 对其进行数值计算并分析其平滑效果和应用可行性。结果表明:焦斑的不均匀性从单独使用透镜列阵时的14%降低到与谱色散平滑结合后的3%;对焦斑点功率谱的分析表明谱色散平滑通过抑制焦斑中高频的频谱强度达到平滑效果。该方案可以进一步提高焦斑平滑效果, 计算结果对实际应用有着重要的参考意义。The laser irradiation non-uniformity of target is required below 5% in inertial confinement fusion (ICF). The scheme of combining smoothing by spectral dispersion (SSD) and lens array (LA) is introduced to meet the above demand, based on the present application LA. The feasibility of the scheme is analyzed by numerical simulation. It shows that the irradiation non-uniformity of focal spot falls down from 14% with LA to 3% with SSD and LA. The result power spectrum analyses of focal spot show that the smoothing effect is caused by middle and high frequency intensity suppression. The scheme can improve the ability of beam smoothing. The results are useful for practical application