Fast electronic and thermal processes in femtosecond laser ablation of Au

Abstract

Velocity distribution, pulse width dependence studies, and two-pulse correlation measurements have been used to study the possibility of the occurrence of ultrafast electronic and thermal ablation processes in Au exposed to ultrashort laser pulses in the femtosecond to picosecond time domain. Three distinct different velocity groups (5.5, 1.5, and 0.25 eV) have been observed and can be attributed to two ultrafast electronic processes (Coulomb explosion and rapid plasma formation) and a thermal process. The buildup of a rapid plasma favors the laser energy absorption around 400 fs after the beginning of the laser-matter interaction.