Emission and electron/ion analysis of the ablated plume from LiYF4 crystals doped with Tm3+ or Nd3+ ions

We performed temporal as well as frequency-resolved emission spectroscopy of the plasma plume generated in vacuum by 355 nm pulsed laser ablation of a LiYF4:Tm3+ crystal (1% Tm3+ concentration) and a LiYF4:Nd3+ crystal (1.5% Nd3+ concentration). The plume emission spectrum is very rich in features and shows the elemental lines belonging to all the components of the host lattice, either neutral or ionized. The time-resolved analysis of some emission features is discussed and some stream velocities are derived. A possible model for the time evolution of the plume components is reported. The electronic detection technique was used to detect the onset of the plasma plume and to measure the ablation laser fluence threshold.