THE YTTRIUM-OXIDE CHEMILUMINESCENCE FROM THE 308 NM EXCIMER-LASER ABLATION OF YBA2CU3O7-X, Y2O3, AND YCL3

The yttrium oxide emission produced in the photoablation Of Y2O3, YCl3 , and YBa2Cu3O7-X in oxygen is investigated. Chemiluminescence from th e B2SIGMA-X2SIGMA and the A2PI-X2SIGMA YO electronic states, produced by the reaction Y+O2, is measured. The intensity of the A2PI3/2 band i s monitored as a function of pressure, distance from the target, and l aser fluence. Hydrodynamic effects have a significant influence on the spatial and temporal evolution of the YO emission in the plume, which is governed by the dynamics of the shock wave generated in the excime r ablation. This shock wave compresses the ambient oxygen and leaves a trough of rarefied oxygen in its wake.