Spatial and Temporal Evolution of Laser-Generated Microplasmas

A study of the evolution of microplasmas produced on aluminum alloy surface at ambient air pressure by 266-nm 10-ns laser pulses with energies of 3 to 100 muJ (2 to 68 GW/cm
²
) is carried out. Gated photography with a minimum width of 5 ns is used to investigate the plasma evolution. Plasma emission and plasma distances from the sample surface are investigated as a function of time. Pulse energy has a strong effect on plasma emission particularly at short delay times. The experimental results are compared with a simplified model of plume expansion