Fig. 4
Results of the two-dimensional particle-in-cell simulation. a The peak intensity of the amplified pulse, as it develops over the 6.7 mm propagation, starting at the focus. b A line-out (solid line) along the x axis of the final intensity envelope after 22.4 ps, given in Fig. 3c. The prediction of Eq. (15) is also shown with the dashed line. c The development of the energy of the amplified pulse. This was found from the two-dimensional data by assuming azimuthal symmetry
