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Dissertation, RWTH Aachen University, 2023; Aachen : RWTH Aachen University Online-Ressource : Illustrationen, Diagramme (2023). = Dissertation, RWTH Aachen University, 2023, The use of laser radiation as a highly flexible tool is well established in many areas of industrial material processing. An adaptation of the laser beam properties to the respective process enables a targeted energy input into the workpiece and an additional increase in productivity and/or the quality of the processing result. In this work, two specific approaches for adapting laser radiation to specific process requirements are discussed and further developed: the generation and adaptation of multi-beam arrays and laser beam shaping. Multi-beam arrays result from the splitting of an input beam into a large number of (usually identical) partial beams. This enables the simultaneous machining of several structures on one or more workpieces with only one beam source. However, the precise relative and absolute positioning of the individual partial beams in multi-beam systems remains a major challenge. Modern laser beam positioning systems lead to the distortion of multi-beam arrays. This results in positioning errors of the partial beams depending on the position of the multi-beam array on the workpiece. Hence, in this work an optical system for the active compensation of 3D positioning errors of individual partial beams in a multi-beam array is developed, implemented and verified as part of a system for laser microstructuring. In addition, a new approach for fully independent 2D positioning of partial beams using modern microsystem scanning mirrors is developed and possible implementations of this approach are discussed. In laser beam shaping, the raw beam profile of a beam source is transformed into a profile adapted to the specific application. Mostly, static beam shaping elements are used for this. However, the flexible adaptation of process parameters and the processing of 3D workpieces require a dynamic adaptation of the respective beam profiles. Existing approaches to highly dynamic laser beam shaping are limited to laser powers below 150 W. Deformable mirrors are an exception to this, but their potential as beam shaping elements has not yet been systematically investigated. In this work, therefore, a systematic, model-based investigation of laser beam shaping by means of deformable mirrors is carried out for different mirror technologies and configurations. In addition, a new concept for the use of high-resolution dynamic beam shaping elements at laser powers above the damage threshold of these beam shaping elements is developed, implemented and investigated using several examples., Published by RWTH Aachen University, Aachen

An optical design and setup for the shaping and dynamic adaptation of an application-adapted intensity distribution is presented. The optics allow for a free rotation of the distribution and a compression of the distribution along an arbitrary axis perpendicular to the optical axis. The compression enables the compensation for the distortion of the distribution on tilted or curved work surfaces.