以ICF系统应用为背景, 建立了四束超短啁啾高斯脉冲远场能量叠加分析模型, 分别对单束及多束超短啁啾高斯脉冲的空间异常特性进行了数值模拟和分析。结果表明: 脉宽是影响超短啁啾高斯脉冲叠加光束产生空间异常现象的主要因素。在利用指数函数复振幅包络的解析式进行分析时, 使用脉宽小于1个光振荡周期的超短啁啾高斯脉冲进行叠加应控制参数在合理的范围内, r<1w0时可有效避免空间异常现象。

According to the application requirement of ICF system, an analysis model of energy superposing on the target plane of four-ultrashort chirped Gaussian pulses was established. By using the analytical expression of the envelope of complex exponential function, the spatial singularity of one pulse and superposition of multi-pulses were analyzed by numerical simulation. The results show that the pulse width is the main factor to influence the spatial singularity phenomenon of the ultrashort chirped Gaussian pulse. While the pulse width was less than one oscillation period, the parameters should be controlled carefully within reasonable horizontal distance, which was less than 1w0 in order to prevent the spatial singularity.