The remarkable temporal properties of ultra-short pulsed lasers in combination with novel beam shaping concepts enable the development of completely new material processing strategies. We demonstrate the benefit of employing focus distributions being tailored in all three spatial dimensions. As example advanced Bessel-like beam profiles, 3D-beam splitting concepts and flat-top focus distributions are used to achieve high-quality and efficient results for cutting, welding and drilling applications. Spatial and temporal in situ diagnostics is employed to analyze light-matter interaction and, in combination with flexible digital-holographic beam shaping techniques, to find the optimal beam shape for the respective laser application.

The modification of transparent materials is enabled by focused ultrashort laser pulses. Single pass processing up to several millimeters can be achieved by the usage of elongated beam profiles. We studied the mechanical separability in dependence of the material thickness. As simulations show, asymmetric beam profiles can cause modifications with preferential direction reducing the necessary breaking force. Pump-probe microscopy is implemented to examine the laser-matter-interaction. We present a measured 3D-reconstruction of the transient interaction inside the material and elucidate the desired crack formation. We demonstrate beam shaping concepts to create a new, efficient and robust class of Bessel-like beams, which can be used to achieve a preferred crack direction. We verify the concept by modification and separation of silicate glasses.

We report on the usage of ultrashort laser pulses in the form of aberration-corrected Bessel-like beams for laser cutting of glass with bevels. Our approach foresees inclining the material's entrance surface with respect to the processing optics. The detailed analysis of phase distortions caused by the beam transition through the tilted glass surface allows precompensating for occurring aberrations using digital holography. We verify theoretical considerations by means of pump-probe microscopy and present high-quality edges in nonstrengthened silicate glass.