Laser driver developments at CEA from the pioneers to the LMJ

The year 2024 will mark the 10th anniversary of the commissioning of the Laser Megajoule (LMJ) Inertial Confinement Fusion Laser first bundle of 8 laser beams. About 400 experiments on target were carried out in this period of time. Currently 11 bundles are in operation at half energy and power for experiments delivering up to 330kJ UV on target. The full system will be completed within few years. In this paper, we take the opportunity of the anniversary to look back from the beginning. We detail an historical review of the laser system development carried out at CEA DAM since 1962. We illustrate the different laser systems built and how they evolved as laser technology evolved with some pioneering results from frequency conversion to pulse compression. We then detail the LMJ design and architecture and focus on laser damage management in the different sub-assemblies of the system. We review the performance reached at half/energy and power with half bundles completed. We finally show the laser campaign performed since 2021 to test the energy/power increase on a few numbers of bundles, preparing the LMJ operation at full performance.