Fig. 2
Numerical integration of the self-similar equations for the limit of a collimated beam (solid line) or a diverging beam (Eq. (12), dashed line). The boundary condition was f(0) = 0 and f′(0) = 0.001, corresponding to a small initial seed. a f as a function of the dimensionless self-similar coordinate β. It tends towards π for both cases. b The development in the f, f′ plane. c The shape of the amplified pulse temporal power envelope, as found from these solutions. Propagation is towards the left
