Comparison of laser polishing effects for different materials

Integrated optical components are becoming more relevant for complex and miniaturized systems. For this application, the necessary free-form objects can only be machined with increased effort when using conventional finishing processes. Therefore, an adjustable finishing process, such as laser polishing, which is a non-contact and low-ablation process, is needed. Due to the increased functionality of these components, multi-material manufacturing is often inevitable. In order to minimize the post-processing effort for these components, a single process step is aimed at. In order to combine this requirement with the laser polishing process, an evaluation has to be performed, whether different material classes can be processed with one laser beam source. Therefore, this paper examines as to what extent a CO2 laser is suitable for polishing fused silica glass, an aluminum alloy and selected polymers. The samples are compared with regard to their line roughness values. In addition, the process windows for the individual materials are determined. Finally, the suitability of laser polishing as a post-processing technique of multi-material components is specified.