Comparison between measured and calculated nonuniformities of Nike laser beams smoothed by induced spatial incoherence

摘要

We have studied the spatial fluence nonuniformities in single beams from the Nike KrF laser smoothed by the Induced Spatial Incoherence (ISI) technique. This study compares time-integrated CCD camera measurements with a numerical model of ISI speckle used in the NRL FAST2D hydrocode, and with analytic calculations that examine the ensemble-aver-age behavior of that model. The results verity the model and calculations, showing good agreement of both the spatial mode spectra and the total nonuniformity versus pulsewidth and bandwidth.