While the cutting of thin glass becomes more and more interesting especially for display applications, direct glass ablation with ps-lasers is a promising technology but not completely understood with respect to ablation and damage mechanisms.
The principal goal of this work is to generate a basic understanding of the ablation process by a combination of simulation4, experimental diagnostics1 and process development2,3.
In this publication the free electron dynamics is discussed, a numerical model is implemented including beam propagation and nonlinear absorption. Finally the results from simulation and experiment are compared.
Major findings achieved with the numerical model so far are:
The critical electron density is adequate / complex enough as a criterion for material removal.
For small pulse durations (<10 ps) ablation criterion is fluence based, for great pulse duration (>10 ps) ablation criterion is intensity based.
The damage mechanism is revealed/identified and qualitatively in good comparison with the experiment.
Beam propagation effects like interference play a major role in the damage mechanisms.