划痕型缺陷对光场质量的影响

为了研究高功率激光系统中划痕型缺陷对光场质量的影响,采用分步傅里叶算法对非线性近轴波动方程进行求解,模拟分析了不同划痕参数(长度、宽度、深度)下,元件内部、光束近场、元件后传输光场以及光束远场的光强分布情况。数值模拟结果表明:随着划痕长度、宽度或深度的增加,元件内部以及元件后传输光场的峰值强度和对比度均会相应增强;光束近场的光强对比度也会略微增大;对于光束远场的强度分布,与划痕宽度方向所对应的频谱能量会不断增强。该项研究工作可以为划痕检验标准的制定提供一定的定量分析依据。

Influence of scratch defects on quality of beam field

In order to research the influence of scratch defects on the quality of beam field in the high power laser system, the non-linear paraxial wave equation is calculated with the split-step-Fourier-transform method. With different parameters of scratch defects, the intensity distribution of the beam field is obtained by using numerical simulation. The simulation results show that the maximum and the contrast of the beam field intensity inside or behind optics increase with the increase of the length, width or depth of the scratch defect. The contrast of the intensity distribution of beam near-field also increases. For the intensity distribution of beam far-field, the spectrum energy corresponding to the width direction of the scratch is enhanced. The study can provide some quantitative analysis bases for the setting of the scratch detection criterion.