Interaction of a laser-produced plume with a second time delayed femtosecond pulse

Time resolved emission spectroscopy coupled with a secondary time-delayed femtosecond pulse technique has been used to study laser–matter interaction that occurs within ablation processes from a solid target, in the 1012–1014W∕cm2 energy range. It allows an examination of the emitted optical signals that characterize the species escaping from the target, namely ions, neutrals, and nanoparticles. Size distributions of nanoparticles are deduced from an analysis of the deposition substrate. The newest result concerns the huge drop of emission signal from the nanoparticles, which occurs at a delay (0.8<Δt<1ns) and has been attributed to a fragmentation process.