Estimation of the depth limit for percussion drilling with picosecond laser pulses

We present a model to predict the final depth of percussion-drilled holes that are produced with picosecond laser pulses in metals. It is based on the assumption that boreholes always have conical geometries when the drilling process terminates. We show that the model is valid for various process parameters when drilling in stainless steel. This was even confirmed by drilling with 3 mJ pulses which resulted in a 10 mm deep borehole without thermal damage. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement