Guided propagation of extremely intense lasers in plasma via ion motion.

Abstract

The upcoming 10-100 PW laser facilities may deliver laser pulses with unprecedented intensity of 10^{22}-10^{25}Wcm^{-2}. Such laser pulses interacting with ultrarelativistic electrons accelerated in plasma can trigger various nonlinear quantum electrodynamic processes. Usually, ion motion is expected to be ignorable since the laser intensities below 10^{25}Wcm^{-2} are underrelativistic for ions. Here, we find that ion motion becomes significant even with the intensity around 10^{22}Wcm^{-2} when electron cavitation is formed by the strong laser ponderomotive force. Due to the electron cavitation, guided laser propagation becomes impossible via usual plasma electron response to laser fields. However, we find that ion response to the laser fields may effectively guide laser propagation at such high intensity levels. The corresponding conditions of the required ion density distribution and laser power are presented and verified by three-dimensional particle-in-cell simulations.