Molecular Dynamics Simulations of Laser-Materials Interactions

Abstract

Atomistic and coarse grained molecular dynamics (MD) simulations of laser-materials interactions are playing an increasingly important role in investigation of complex and highly non-equilibrium processes involved in short pulse laser processing and surface modification. This role is defined by the ability of MD simulations to reveal the microscopic mechanisms of structural and phase transformations induced by the laser excitation and, at the same time, to provide clear visual representations, or “atomic movies,” of laser-induced dynamic processes. In this presentation, the atomistic and coarse-grained (mesoscopic) computational methods developed for simulation of laser-materials interactions will be briefly reviewed and the capabilities and limitations of these methods will be discussed. The introduction to the computational methods will be followed by several examples of atomistic simulations of laser melting, generation of crystal defects and nanoscale surface morphology, photomechanical spallation, explosive boiling and molecular entrainment in laser ablation. The discussion of the results will be connected to the basic concepts of thermodynamics and kinetics of materials and will be aimed at providing a clear physical picture of the structural and phase transformations triggered by the rapid laser energy deposition. The results of the simulations will be related to experimental observations. The implications of the computational predictions for practical applications, as well as for the theoretical description and continuum-level modeling of the laser-induced processes will be discussed.