‘‘Flicker’’ in small scale laser–plasma self-focusing

Abstract
Small amplitude, short wavelength ion acoustic waves in laser‐produced plasmas cause fluctuations in the trajectories of light rays that can lead to time‐dependent, self‐sustaining shifting of focal spots and a somewhat random redistribution of the light near the critical surface. This flickering is seen in simulations involving small scale beam inhomogeneities over a uniform background laser profile, which model the center of a realistic laser beam. The effect can cause significant intensity multiplication in long scale length high‐Z plasmas with only modest beam imperfections.