Ultrashort-pulse laser drillingFenteng, Eric Agyei Owusu (Avtor) Gregorčič, Peter (Mentor) femtosecond laser ablationlaser drillinglaser ablation thresholdincubation effectheat accumulationd-squared methodrepetition ratethin foilThe ablation threshold and incubation behaviour were compared for stainless steel 316L and tungsten in foil (50 µm) and bulk (3 mm) forms under femtosecond (300 fs) laser irradiation. The threshold fluence and incubation coefficients were measured using the diameter-squared (D$^{2}$) method at repetition rates of 1 kHz, 333 kHz and 2 MHz with number of pulses ranging from 1 to 1000. Foil and bulk samples gave similar results. The threshold fluence decreased with the number of pulses and showed a trend toward saturation above 1000 pulses. The incubation coefficients remained stable at all repetition rates applied. LIPSS formed near the threshold. Surfaces smoothed with melting at higher fluences and roughened further due to phase explosion. [E. A. O. Fenteng]20262026-09-29 08:30:43Magistrsko delo/naloga188814sl