Excimer laser ablation of solids with laser power densities in the range 106 to 109 W/cm2 is becoming increasingly important in laser processing of materials for microelectronics. The ablation process produces an intense plume of gas phase material which expands rapidly away from the ablated surface. We report on real time interferometric measurements of free electron density and laser induced fluorescence studies of atoms and molecules in the plume, with the objective of understanding the dynamics of material ablation.