Beam smoothing effect of induced spatial incoherence combined with continuous phase plate is reported. General theoretical models that can be used to describe the spatiotemporal characteristics of the focal region in beam smoothing is proposed. The focal region evolution using induced spatial incoherence is studied and compared with that of using smoothing by spectral dispersion. The result shows that, when using induced spatial incoherence combined with continuous phase plate for beam smoothing, the focal region spatiotemporal evolution is chaotic and random, and the size of speckle on spacetime is determined by the coherence time of the laser. The comparison shows that the smoothing speed of induced spatial incoherence is higher. Focal spot time-resolved spectrum and focal spot intensity distribution using induced spatial incoherence are measured experimentally. The results show that the beam smoothing method has an excellent ability to obtain the desired low coherence in focal region, and can completely suppress the middle-high frequency nonuniformity of the focal spot.

报告了诱导空间不相干与连续相位板相结合的光束平滑效应。提出了可用于描述光束平滑聚焦区域时空特性的通用理论模型。研究了使用诱导空间不相干的焦点区域演化，并与使用光谱色散平滑的焦点区域演化进行了比较。结果表明，当使用诱导空间不相干结合连续相位板进行光束平滑时，焦点区域时空演化是混沌和随机的，时空散斑的大小由激光的相干时间决定。比较表明，诱导空间不相干的平滑速度更高。焦斑时间分辨光谱和焦斑强度分布使用诱导空间不相干实验测量。结果表明，光束平滑方法在获得所需的焦区低相干性方面具有优异的能力，可以完全抑制焦斑的中高频不均匀性。