Experimental study on the ablation of stainless steel using multiple ultra-short laser pulses with tunable time delays

Results on the ablation of stainless steel using ultra-short single, double and quadruple pulses as a function of the fluence and the time delay between each laser pulse are presented. The investigations focused quantitatively on the ablated volume and the resulting ablation efficiency, and qualitatively on the topography of the structures produced, providing insights about physical mechanisms such as shielding, re-deposition of ablated particles, and accumulation of heat or energy. The results indicate a significant influence of fluence in combination with the time delay on the ablation process and the resulting ablation topography.