sentences:  From 1996 to 1997 the GEKKO system was upgraded with a ~0.4 kJ, 0.5 PW ultra-short pulse beam which was used to investigate a promising new technique of ICF known as "fast ignition", where the compression phase of target implosion is decoupled from the heating phase.GEKKO, using the petawatt beam for heating, along with the original beams for compression, demonstrated a fusion yield enhancement of 3 orders of magnitude when the petawatt beam was used.GEKKO is currently being upgraded with the addition of a second "side-by-side" laser, the LFEX ("Laser for Fast Ignition Experiment"), part of the FIREX-1 program, in order to deliver a 10 kJ pulse of energy to a target in 10 picoseconds, further exploring the fast ignition regime.