Fig. 2: AC Stark shift and dynamical Franz-Keldysh effect revealed by time-resolved non-collinear spectroscopy.
From: Noncollinear harmonic spectroscopy reveals crossover of strong-field effects
a The main mechanisms of HHG in solids involving interband polarization and intraband currents within a pump-probe geometry. Note that \(\Delta t > 0\) indicates that the pump pulse precedes the probe pulse. The pulse duration of the pump and probe is 25 and 28 fs, respectively. b, c The experimentally measured and numerically simulated time-resolved (0, 3) (third harmonic, H3) spectra of the probe pulse. The coloured dashed line in the measured and simulated spectra depicts the spectral shift of the third-harmonic energy \(\Delta {E}^{(0,3)}\). The laser pulses are polarized along the Γ-K direction of the Brillouin zone for both the measured and simulated spectra. The color bars are normalized to their maximum harmonic yields and presented on a logarithmic scale.
