Evaluating Beam Quality And It's Application In Propagation Of High Power Laser Beams

Inertial Confinement Fusion (ICF) is an important research field today, which has an important scientific significance and application value in developing the new energy resource. The work presented in this paper is tightly connected with ICF.The main factor limiting the output energy and efficiency of high power solid state laser drivers used in ICF is the small-scale self-focusing. In this paper, we introduce high-order contrast to characterize the quality of beams. We introduce high-order contrast for characterizing the near field uniformity. The application of high-order contrast is shown by theoretical analyze and numerical calculation in linear and nonlinear propagation. Comparing these numerical results, especially, we find third-order contrast and forth-order contrast are better than fill factor, modulation, and contrast for describing the uniformity of high intensity laser beam in near field. And it can monitor well the filamentation to avoid small-scale self-focusing.The physical model and algorithm of numerical simulation in high power laser driver for ICF are given. We analyze the effect of spatial sampling and dimensions by examples.