Congratulations to Evaldas Kažukauskas on the successful defence of his PhD thesis in Physics, titled Femtosecond Laser Ablation and Surface Roughness Control. Supervisor – Dr Simas Butkus.
During the defense, the dissertation committee praised the clarity and compelling narrative of the work, noting that the thesis presents data and interpretations so engagingly that it naturally sparks curiosity and lively discussion—even among those outside the immediate field. The board also commended the candidate's scientific rigor and the immense volume of experimental work completed over the course of his research.
Femtosecond laser ablation is a material-processing technique used to create high-resolution, complex structures. However, the process also alters the surface texture of the material, which can significantly affect the optical, mechanical, chemical, and functional properties of the final component.
The dissertation investigates the physical mechanisms governing the formation and evolution of surface roughness during femtosecond laser ablation and develops strategies for its precise control.
Using spatial and spectral analysis methods, the research examines surface evolution under different laser-processing conditions, scanning strategies, and initial surface states, providing new insights into the factors that influence surface texture.
The findings provide new insights into the mechanisms underlying surface roughness formation and demonstrate how it can be accurately controlled. Rather than an unavoidable consequence of laser processing, surface roughness emerges as a material property that can be deliberately tailored. These results may help improve processing quality and broaden the application of laser micromachining technologies. Thesis abstract.