Götte Agustín, Sallese Marcelo, Ränke Fabian, Voisiat Bogdan, Lasagni Andrés Fabián, Soldera Marcos
Institut für Fertigungstechnik, Technische Universität Dresden, George-Bähr-Str. 3c, 01069 Dresden, Germany.
Fraunhofer-Institut für Werkstoff- und Strahltechnik IWS, Winterbergstr. 28, 01277 Dresden, Germany.
Sensors (Basel). 2025 Aug 13;25(16):5031. doi: 10.3390/s25165031.
Monitoring of laser-based processes is essential for ensuring the quality of produced surface structures and for maintaining the process stability and reproducibility. Optical methods based on scatterometry are attractive for industrial monitoring as they are fast, non-contact, non-destructive, and can resolve features down to the sub-microscale. Here, Laser-Induced Periodic Surface Structures (LIPSS) are produced on stainless steel using ultrashort laser pulses in combination with a polygon scanning system. After the process, the fabricated LIPSS features are characterized by microscopy methods and with an optical setup based on scatterometry. Images of the diffraction patterns are collected and the intensity distribution analyzed and compared to the microscopy results in order to estimate the LIPSS height, spatial period, and regularity. The resulting analysis allows us to study LIPSS formation development, even when its characteristic diffraction pattern gradually changes from a double-sickle shape to a diffuse cloud. The scatterometry setup could be used to infer LIPSS height up to 420 nm, with an estimated average error of 7.7% for the highest structures and 11.4% in the whole working range. Periods estimation presents an average error of ~5% in the range where LIPSS are well-defined. In addition, the opening angle of the LIPSS was monitored and compared with regularity measurements, indicating that angles exceeding a certain threshold correspond to surfaces where sub-structures dominate over LIPSS.
对基于激光的加工过程进行监测对于确保所生产表面结构的质量以及维持过程稳定性和可重复性至关重要。基于散射测量的光学方法因其快速、非接触、无损且能够分辨至亚微米级特征而对工业监测具有吸引力。在此，使用超短激光脉冲结合多边形扫描系统在不锈钢上产生激光诱导周期性表面结构（LIPSS）。加工完成后，通过显微镜方法以及基于散射测量的光学装置对制造的LIPSS特征进行表征。收集衍射图案的图像并分析强度分布，并与显微镜结果进行比较，以估计LIPSS的高度、空间周期和规则性。由此产生的分析使我们能够研究LIPSS的形成发展，即使其特征衍射图案逐渐从双镰刀形状变为弥散云状。散射测量装置可用于推断高达420 nm的LIPSS高度，对于最高结构估计平均误差为7.7%，在整个工作范围内为11.4%。在LIPSS定义明确的范围内，周期估计的平均误差约为5%。此外，对LIPSS的开口角度进行了监测并与规则性测量结果进行比较，表明超过特定阈值的角度对应于亚结构主导LIPSS的表面。
