Fig. 2: Retrieval of the XFROG trace.
From: Photon deceleration in plasma wakes generates single-cycle relativistic tunable infrared pulses
a, b Measured and retrieved XFROG traces. The two dashed boxes in (b) are the FWDFG signals generated by MIR (1.5–6 μm) and LWIR (6–20 μm) components, respectively. c, d Retrieved IR temporal and spectral intensity and phase. The intensities are shown on a logarithmic scale. The dashed black line in (d) shows the original spectrum of the 810 nm drive laser. e, f Retrieved LWIR temporal and spectral intensity and phase. The gentle quadratic phase variation shown in (e) and (f) is consistent with a small linear chirp seen in (a).
