Imaging of the Fluorescence Created by Ablation of Y 2 O 3,BaO 2,CuO,and YBa 2 Cu 3 O 7– x by 308-nm Laser Light

A gated intensified CCD camera is used to acquire time-resolved images of the plume generated from the excimer laser ablation of CuO, BaO₂, Y₂O₃, and YBa₂Cu₃O_7–x pellets in vacuum, He, or O₂. Narrow (12-nm FWHM) bandpass filters are used to select emission from individual species within the plume. The spatial and the temporal evolution of the emission is unique for each of the ejected ions, atoms, and diatomics. A luminous shock front, i.e., a blast wave, is observed at pressures greater than 1 Torr in He and 0.1 Torr in O₂. The propagation of this shock front is suitably described by scaling factors that were previously developed to describe the shock waves from a point explosion. Images of emission from atomic Cu and O were acquired after the ablation of CuO. These images imply that ion/electron bombardment is significant within the plasma plume. The time dependence of the images shows the evolution of the shock wave and suggests the origin of the luminous plume.