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 the B2SIGMA-X2SIGMA and the A2PI-X2SIGMA YO electronic states, produced by the reaction Y+O2, is measured. The intensity of the A2PI3/2 band is monitored as a function of pressure, distance from the target, and laser 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 excimer ablation. This shock wave compresses the ambient oxygen and leaves a trough of rarefied oxygen in its wake.