Multiphase simulation of nanosecond laser ablation of silicon: from evaporation-dominated to high-irradiance regimes

Abstract

Nanosecond laser ablation of silicon exhibits a transition from moderate to strongly enhanced material removal at high irradiances that remains difficult to reproduce numerically. In this work, single-shot ablation of monocrystalline silicon at 355 nm is simulated using a compressible multiphase Mass-of-Fluid model implemented in an OpenFOAM-based solver. Simulations were performed for Gaussian spatial and temporal laser profiles with 44 ns pulse duration and over an irradiance range from 2 × 10⁸ to 1.93 × 10¹⁰ W cm⁻². Good agreement with experimental ablation depths is obtained in the low- and intermediate-irradiance regimes, while the abrupt increase observed experimentally at the highest irradiance remains underestimated, indicating the importance of plasma dynamics and near-critical phase transition processes.