title: Self-compression of laser pulses in plasma.
abstract: We study self-compression of weakly relativistically intense laser pulses in subcritical plasmas using one- (1D) and three-dimensional (3D) direct particle-in-cell (PIC) simulations. The self-compression works in the density window from 1/4 critical to slightly below critical density, where the Raman instability is prohibited. An analytical model is developed to describe the self-compression. The model admits pulsing Gaussian solutions and a long-lived running soliton solution. The 1D PIC results agree well with the analytical model, and compressions by an order of magnitude are observed. In the 3D geometry, the longitudinal self-compression competes with the transverse self-focusing/filamentation. To damp the filamentation we use a periodic plasma-vacuum structure. The 3D PIC simulations suggest that a 30 fs long laser pulse is efficiently compressed to 5 fs.
authors.affiliation: Institut fur Theoretische Physik I, Heinrich-Heine-Universitat Duesseldorf, 40225 Duesseldorf, Germany.
authors.forename: O
authors.initials: O
authors.lastname: Shorokhov
authors.forename: A
authors.initials: A
authors.lastname: Pukhov
authors.forename: I
authors.initials: I
authors.lastname: Kostyukov