Theoretical study of characteristics of laser-drilling with a Gaussian beam and a top-flat beam in time domain

Laser drilling has been more and more widely used in laser machining process. Therefore, optimizing the quality of laser drilling becomes extremely important. We know that laser drilling can be achieved by using high power density of a laser. As light waves with different waveforms represent the different energy distributions in time domain, we believe that the quality of laser drilling should be related to the laser waveform. At present, a laser used in the laser processing usually hasthe waveform with a Gaussian or a Lorentzian distribution. In this study, we numerically simulated the punching quality of a pulsed laser with the Gaussian distribution and a pulsed laser with the top-flat distribution (we called it as a square-shaped laser pulse) at the same energy. It mainly refers to the changes of density, temperature, and pressure of the target materials under the same energy for different waveforms. The constrained interpolation profile algorithm has been used to simulate the machining process. Until now, there are few studies on the features of laser drilling with different waveforms in time domain. This paper provides a new method to optimize the quality of laser drilling.