Figure 4: Double-bended saturation.

Four distinct regimes of saturation behaviour are as follows: (A) linear regime at very low pump fluences, (B) low-fluence out-scattering dominated regime; (C) intermediated regime, where the impact of in-scattering becomes significant and (D) the high-fluence regime, where Pauli blocking leads to a saturation. (a) Double-logarithmic plot of Fig. 1c showing the numerically evaluated saturation behaviour of (red squares) and the corresponding (blue line) low- and (green line) high-fluence fit according to equation (1). (b) Time delay between the centre of the excitation pulse and the time when (t) becomes maximal as a function of the pump fluence.