Challenges in Spatial Beam Shaping for Ultrafast Laser Surface Texturing: Role of SLM-Induced Artifacts (Invited Paper)

Ultrafast laser processing offers unique opportunities for micro- and nanoscale structuring of metallic surfaces, particularly for biomedical applications. In this work, we explore femtosecond laser pulses that are spatially shaped and temporally controlled to achieve precise surface texturing on titanium alloys. Beam shaping is performed using a Spatial Light Modulator (SLM), enabling complex profiles such as vortex beams. However, imperfections in the SLM introduce parasitic diffraction orders and residual phase errors, which compromise the fidelity of the laser-material interaction. We experimentally assess the impact of these artifacts on surface morphology through quantitative analysis. Deviations from the ideal beam profile result in irregular patterns and reduced reproducibility, with vortex beams showing being highly sensitive to phase distortions. These results underline the critical role of beam-shaping accuracy in achieving predictable and controlled surface features.