Advanced design of the third-harmonic generation and focusing system of the Laser Megajoule

Summary form only given. The Laser Megajoule is designed for delivering on target 2 MJ at 351 nm with a shaped pulse for high-energy physics experiments. To achieve this goal 240 Nd:glass amplifier chain operating at 1053 nm with 38-cm square beams will be used. These beams divided in 60 quadruplets (matrix of 2 by 2) have to be frequency tripled before being focused to irradiate the target.