Broadband phase conversion of the frequency tripled Omega laser

One year ago, implementation of distributed phase plates on the twenty-four frequency tripled beamlines of the Omega laser system had increased the overall irradiation uniformity to an --10% (rms) level. Target performance increased as a result of reducing the irradiation hot spots due to normal beam focusing. However, target performance did not improve to the level of theoretical predictions. At the Laboratory for Laser Energetics, the authors spent the last year reviewing the various aspects of irradiation uniformity. Issues such as beam pointing and focusing, beam to beam timing, and energy balance and spatial uniformity are analyzed in this paper