Numerical simulation of copper ablation by ultrashort laser pulses

TL;DR

This study uses a hydrodynamic simulation to analyze copper ablation by ultrashort laser pulses, revealing threshold behaviors, ablation regimes, and plasma effects relevant for microfabrication.

Contribution

It introduces a modified hydrodynamic model to simulate copper ablation, providing new insights into ablation thresholds, depth regimes, and plasma shielding effects.

Findings

Ablation threshold is nearly constant in femtosecond regime.

Ablation depth varies with pulse duration, showing four regimes.

Plasma shielding influences ablation depth significantly.

Abstract

Using a modified self-consistent one-dimensional hydrodynamic lagrangian fluid code, laser ablation of solid copper by ultrashort laser pulses in vacuum was simulated to study fundamental mechanisms and to provide a guide for drilling periodic microholes or microgratings on the metal surface. The simulated laser ablation threshold is a approximate constancy in femtosecond regime and increases as the square root of pulse duration in picosecond regime. The ablation depth as a function of pulse duration shows four different regimes and a minimum for a pulse duration of ~ 12ps for various laser fluences. The influence of laser-induced plasma shielding on ablation depth is also studied.