Ultra-intense laser field amplification from a petawatt-class laser focusing in moderate density plasma

The rapid development of laser technologies promises a significant growth of peak laser intensity from 10²² W/cm² to >10²³ W/cm², allowing the experimental studies of strong field quantum-electrodynamics physics and laser nuclear physics. Here, we propose a method to realize the ultra-intense laser field amplification of petawatt-class laser pulse in moderate density plasma via relativistic self-focusing and tapered-channel focusing. Three-dimensional particle-in-cell simulations demonstrate that almost an order of magnitude enhancement of laser intensity is possible even though the γ-ray radiation results in massive laser energy loss. In particular, with a seed laser intensity of ∼10²³ W/cm², duration of 82.5 fs and power of 31 petawatt, one can obtain ∼10²⁴ W/cm² intensity and up to ∼60% energy conversion efficiency from the initial seed laser to the focused laser in plasma with density of 3.3 × 10²²/cm³. This may pave the way to the new research field of ultra-intense laser plasma interaction in the upcoming laser facilities.