Filamentation and forward Brillouin scatter of entire smoothed and aberrated laser beams

Laser-plasma interactions are sensitive to both the fine-scale speckle and the larger scale envelope intensity of the beam. For some time, simulations have been done on volumes taken from part of the laser beam cross-section, and the results from multiple simulations extrapolated to predict the beha vior of the entire beam. However, such extrapolation could very well miss e ffects of the larger scale structure on the fine-scale. The only definitive method is to simulate the entire beam. These very large calculations have not been feasible until recently, but they are now possible on massively pa rallel computers. Whole beam simulations show the dramatic difference in th e propagation and break up of smoothed and aberrated beams. [S1070-664X(00) 96505-4].