针对多色、多频光谱角色散束匀滑方案，数值模拟和分析了多色波长差、多频波长差、带宽和色循环数等主要参数对远场光场均匀性的影响，进而对相关参数进行了优化。结果表明，随着多色波长差的增加，远场焦斑均匀性呈先变好后降低的趋势，即存在最佳波长差；当多频波长差和带宽增加时，远场光场均匀性均得到改善，但考虑高效三倍频的影响，多频波长差和带宽均不宜取太大。当光栅色散系数不变时，远场光强对比度随色循环数的增大呈先减小后增大的趋势，即存在最佳色循环数的选择问题，但最佳色循环数并不为1，而是随着光源参数和光栅参数的变化而有所变化。

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.

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。

To improve the ability of beam smoothing in the device of inertial confinement fusion (ICF) in China, the theory of smoothing by spectral dispersion (SSD) is studied, and some experiments are carried out to analyze the mechanism of SSD in contrast with another technology of smoothing—distributed phase plane (DPP). It is found that the uniformity of focal spot in direction of dispersion is improved markedly using sinusoidal phase modulation (PM) and dispersion in SSD. And the intensity modulation of focal spot in this direction is smoothed by SSD. According to the experiments results, the changes of spectral intensity of spatial frequency at low-mode are very limited, and at high-mode are obviously; the nonuniformity varies from 40% to 12.5%. The ability of smoothing depends on the parameter of SSD. It also shows that the color cycle is very important in the process of smoothing, although the smoothing by broaden of laser spectral width for PM is poor.

为提高国内惯性约束聚变(ICF)装置的焦斑平滑能力，在对光谱色散平滑(SSD)技术理论分析的基础上，开展相关实验并研究其平滑机制。实验结合另一种焦斑平滑技术——分布式相位板(DPP)比较分析光谱色散平滑技术应用下的焦斑均匀性的变化。实验表明，利用光谱色散平滑技术中的正弦相位调制对光谱展宽并色散后，在色散方向上的焦斑均匀性有明显改善，120 μm内的光强调制被平滑，其平滑能力依赖于光谱色散平滑技术参量的选择;焦斑的低频光谱强度变化很小，但中高频光谱强度下降，焦斑质量有良好的改善，焦斑的不均匀性从40%降低到12.5%。结果还表明，光谱色散平滑技术中的关键是色循环的产生，光谱本身加宽产生的平滑作用非常有限。

Irradiation uniformity of laser on target is very important for inertial confinement fusion (ICF). The theory of smoothing by spectral dispersion (SSD) in ICF is studied by translation theory of optic, and with whether using of SSD and different parameters of SSD, the variations of irradiation nonuniformity of the surface of target are numerically simulated combined with random phase plate (RPP). The results show that application of SSD can reduce the irradiation nonuniformity of the surface of target, the variations of irradiation nonuniformity with the time are oscillating at the beginning and drive to a constant in the end. When the number of color cycle is small, the broader of laser bandwidth and the better effect of SSD are obtained.

利用光传输理论对ICF驱动器中使用的光谱色散平滑(SSD)技术作了理论分析,并结合典型的随机相位板(RPP)技术,用计算机模拟了使用光谱色散平滑技术前后激光靶面辐照不均匀性的变化及其技术中不同带宽和调制频率下激光靶面辐照不均匀性的变化。