Laser Surface Functionalization from Fundamentals to Application

In the last decade stable ultra-short pulsed (USP) laser systems have become more widely available and are especially useful to ablate materials in a defined manner. Using small pulse energies mitigates heat input to the specimen useful for removing heat-sensitive materials. The exact ablation mechanism is still controversially discussed and as well the formation of sub-wavelength ripples. Utilizing laser radiation for microstructuring and cutting can potentially bridge the manufacturing feature-size gap of conventional techniques and clean room technology enabling innovative applications. However, there is a need in developing novel machine tool concepts and processing strategies with respect to a certain use considering this force-free process. In order to tailor the functionality governed by topography and chemistry, the ablation effects have to be unraveled exploiting the use of USP laser machining routines. Light-matter interaction mechanisms leading to ablation and evolution of self-assembled micro- and nanostructures have to be controlled transferring these unique patterns to application. This thesis presents experimental configurations developed to address the challenges just described. The test-beds consist of a combination using mechanical and optical axes encompassing a USP laser system, modifying optics and a beam delivery. Combined processes with radial and quasi-tangential irradiation condition are established for a fast production, where the controller speed is identified being the bottleneck for further acceleration. The impact of laser machining to the specimens is discussed based on microscopy and spectroscopy data using photons and electrons. Fundamental studies on single- and multi-pulse ablation reveals precursor ripple structures as origin of cone-like-protrusions (CLP) observed at steel samples. Stop-motion imaging combined with micro-structural assessments points to an evolution of topology from laser-induced periodic surface structures (LIPSS) - supra-wavelength ripples - to CLP after ...