Third-harmonic generation studies with coherent and fiber-smoothed pulses for megajoule class lasers

Summary form only given. In this paper, we present results we have obtained on our new experimental setup dedicated to harmonic generation study at high fluences on large aperture beam. The experiments are conducted on the backlighter beamline of Phebus, which typically delivers up to 1250 J at 1053 nm on a 19-cm-diameter beam in a 1.3-ns square pulse to reach a 3.5 GW/cm/sup 2/ intensity at the input of the KDP crystals.