In order to investigate the overlap rate of an ablated spot on monocrystalline silicon by a femtosecond laser, a skewness spot derived from plasma is analyzed. First, the serial spot image is collected, and the ablated core area of the spot is extracted by the way of bit image layering so that the peripheral halo can be eliminated effectively. The image of the spot is enhanced by Gaussian-guided filtering, which has the effect of keeping the edge of the spot; the smoothness of different directions is the same, and the gray distribution is more uniform. Second, the two-domain product gray centroid method is introduced to extract the spot centroid; at the same time, considering the information of spatial domain and value domain, the standard deviation is reduced by1.0. Third, according to the characteristics of spot shape change, the centroid coordinates are tracked by the Kalman filter optimized by wavelet heteropoly denoising, and the error is reduced by 0.5. Finally, the distance proportion sum method is introduced to calculate the diameter of the deflection spot, and then, by using the optimal tracking method, the average change in speed of the spot in the transverse direction is found to be 0.07 mm/s. The result of this paper shows that, on the one hand, with the increase of laser power, the influence factor of spot deflection on the spot diameter is increasing but the increase in the amplitude is gradually reduced. It can be seen that the increase of laser power can slow down the influence of spot deflection on spot overlap. Between 10 and 20 mW, strong increasing effect is shown; however, between 20 and 50 mW, a weak increasing effect is shown. On the other hand, strictly speaking, it is not the scanning speed but the actual ablation speed that has a direct impact on the spot overlap rate.

中文翻译：

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飞秒激光烧蚀单晶硅光斑重叠率分析

为了研究飞秒激光在单晶硅上烧蚀光斑的重叠率，分析了源自等离子体的偏斜光斑。首先采集串行光斑图像，通过位图分层的方式提取光斑烧蚀的核心区域，有效消除外围光晕。光斑图像经过高斯引导滤波增强，具有保持光斑边缘的效果；不同方向的平滑度相同，灰度分布更均匀。其次，引入双域乘积灰度质心法提取点质心；同时，考虑到空间域和值域的信息，标准差减少了1.0。三、根据光斑形状变化的特点，质心坐标由小波杂多降噪优化的卡尔曼滤波器跟踪，误差降低0.5。最后，引入距离比例求和法计算偏转光斑直径，采用最优跟踪法求得光斑横向平均速度变化为0.07 mm/s。本文的结果表明，一方面，随着激光功率的增加，光斑偏转对光斑直径的影响因素在增加，但幅度的增加逐渐减小。可见，增加激光功率可以减缓光斑偏转对光斑重叠的影响。在 10 到 20 mW 之间，显示出强烈的增加效果；然而，在 20 到 50 mW 之间，显示出微弱的增加效果。另一方面，