Figure 4.

Measured and normalized THz traces emitted from shift currents (${\mathbf{e}}_{\mathrm{shift}}$, black lines) and AH currents (${\mathbf{e}}_{\mathrm{AH}}$, green lines) for two different optical peak intensities: I _low = 13 MW/cm² (a) and I _high = 130 MW/cm² (b) and for an excitation photon energy of 1.476 eV, i.e., 60 meV above the bandgap of GaAs. The red lines (${\mathbf{e}}_{\mathrm{conv}}$) denote the THz traces resulting from a convolution of the current pulses shown in the insets with an inverse Fourier transformation of ${\mathbf{E}}_{\mathrm{shift}}/{\mathbf{I}}_{\mathrm{opt}}$.