VULCAN and FLAME ultra-short pulses characterization by GROG algorithm

The complete characterization of the laser pulse parameters was made using a new algorithmic method: GRenouille/FrOG (GROG), based on the 1D Conjugate Gradient Minimization Method. The purpose is, analyzing experimental FROG/GRENOUILLE traces, to accurately retrieve intensity and phase both in the temporal and spectral domain so as to completely characterize an ultra short high power laser pulse. This algorithm shows important features in the reconstruction of many different pulse classes. The GRENOUILLE traces of FLAME Probe line pulses (60 mJ, 70 fs, 10 Hz) were acquired in the FLAME Front End Area (FFEA) at the Laboratori Nazionali di Frascati (LNF), Instituto Nazionale di Fisica Nucleare (INFN). A FROG diagnostic is being developed in Central Laser Facility in RAL able to characterize the 100 J, 1.4 ps, 2 nm @ 1053.5 nm laser pulses in Target Area West (TAW).