Simulations of short pulse laser-matter interaction in case of tight focusing onto thin film

Abstract

Studies of ultra-fast laser-matter interaction are important for many applications. Such interaction triggers extreme physical processes which are localized in the range from ~10 nanometers to micron spatial scales and developing within picosecond−nanosecond time range. Thus the experimental observations are difficult and methods of applied mathematics are necessary to understand these processes. Here we describe our simulation approaches and present solutions for a laser problem significant for applications. Namely, the processes of melting, a liquid jet formation, and its rupture are considered. Motion with the jet is caused by a short ~0.1−1 ps pulse illuminating a small spot on a surface of a thin ~10 − 100 nm film deposited onto substrate. We find the 5-fold symmetry structures in the frozen jet and appearance of very sharp tip of the jet.