J.-C. Gauthier, et al.
J. Phys. IV France 133 (2006) 669-672
Design, optimization and development of pulse compression gratings for the MPW-HE LILJ. Néauport and N. Bonod
Commissariat à l'Énergie Atomique, Centre d'Études Scientifiques et Techniques d'Aquitaine, BP. 2, 33114 Le Barp, France
The french Commissariat à l'Energie Atomique (CEA) develops a multipetawatt laser in the Laser Integration Line (LIL), prototype of the future Megajoule Laser . This Petawatt laser line will deliver impulsions of 7.2 PW, 500 fs at the wavelength of 1053 nm. The chirped pulse amplification (CPA) method is used . We work on the modelization and the fabrication of gratings used in the CPA scheme. Since damage threshold of more than 3 J/cm2 @ 500fs are needed, we retained multidielectric gratings (MLD) instead of classical gold gratings. These gratings, developed in mid 90's, consist in a multidielectric mirror stack with its top layer engraved with a grating structure. We have been working to optimize the groove geometry of the MLD grating to minimize the E field maximum in the structure. An innovative design using a mixed metal/dielectric mirror stack was also studied. The scope of this paper is to present our main numerical results in these different domains.
© EDP Sciences 2006