IMAGING OF THE FLUORESCENCE CREATED BY ABLATION OF Y2O3, BAO2, CUO, AND YBA2CU3O7-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 YBa2Cu3O7-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 emiss ion is unique for each of the ejected ions, atoms, and diatomics. A lu minous shock front, i.e., a blast wave, is observed at pressures great er 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 d eveloped 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 with in the plasma plume. The time dependence of the images shows the evolu tion of the shock wave and suggests the origin of the luminous plume.