Modeling of systems for broadening of spectrum of petawatt laser pulses and for their nonlinear compression

We numerically model the propagation of high-power laser pulses in a periodic system of nonlinear elements separated by spatial retransmitter filters. We show that, if the accumulated phase difference in an individual nonlinear element is restricted by a value smaller than 1.6 rad, it is possible to obtain the total accumulated phase difference greater than 14 rad while preserving the high radiation brightness. The considered scheme can be used for compressing superpower laser pulses.