Reacting dynamics of the laser ablation plume

Pulsed laser ablation of metals and oxides have been carried out under controlled conditions. Process control parameters such as laser power, laser excitation voltage, beam focus, chamber pressure, substrate temperature, pulse repetition rate, and target rotation rate were changed and the outputs analyzed. The real-time signature of the plume has been studied and characterized. These experimental results are compared with mathematical models of the ablation process and the supersonic plume propagation wave. We can explain with reference to the correlation of real-time spectroscopy some anomalies present in the ablation process involving the non-equilibrium production of oxides. In the computational model for the reacting pulsed-laser ablation plume, the stoichiometry depends on input energy via a prescribed inlet velocity, density, and temperature, which are calculated at the edge of a Knudsen layer. We conclude that a sharp reaction front promotes a quick rise to desired stoichiometry, which can be important in applications involving deposition onto substrates. © 2003 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.