Diagnostics of nanosecond dynamics of the plasma produced during KrF excimer laser ablation of zirconia in vacuum

A 248 nm KrF excimer laser was used to ablate the yttria stabilized ZrO2 target in vacuum while an intensified charge coupled device camera was used to get the time-resolved side view images of the induced plume/plasma. Two components, plume and plasma, can be clearly distinguished from the images with delay time less than 300 ns. The center of the plasma is found moving along the direction tilted similar to55degrees, instead of 90degrees, from the surface of the target while the processing laser came along similar to40degrees. The movement velocities and the explosion rates of the plasma during the first 2 mus after the laser strike were calculated. Time- and spatial-resolved emission spectra from excited Zr atoms in the plasma have been measured to determine the corresponding excitation temperature. The dynamic evolution of the plasma is outlined based on the experimental results. (C) 2002 American Institute of Physics.