Femtosecond laser ablation of CaF2: plasma characterization and thin films deposition

Nanostructured thin films of CaF2 have been deposited in vacuum by ultra-short pulse laser ablation. The laser-induced plasma, characterized by optical emission spectroscopy and ICCD fast imaging, shows the presence of Ca and F atomic species, neutral and ionized, together with the CaF molecular species. Although continuous blackbody-like emission has not been detected from the plasma, the deposited films, characterized by Scanning Electron Microscopy and X-ray Photoelectron Spectroscopy, are apparently formed by the coalescence of a large number of nanoparticles composed by stoichiometric CaF2