Fig. 1. Architecture of the neural network used for reconstructing the molecular alignment from the FROG trace. The inset shows the architecture of the Inception block.

Fig. 2. (a) Simulated example of the M-XFROG trace. (b) M-XFROG trace constructed using the probe pulse and molecular alignment reconstructed by our network. (c) The reconstructed temporal intensity and phase of the probe pulse (solid lines). The dashed lines show the ground truth for comparision. (d) The reconstructed molecular alignment factor ⟨cos²θ⟩(t) (solid line). The dashed line shows the ground truth for comparision.

Fig. 3. Schematic diagram of the experimental setup. BS, beamsplitter; HWP, half-wave plate; BM, Brewster mirror; DL, delay line; BBO, BaB₂O₄; P, polarizer; BD, beam dump; GC, gas cell; CM, concave mirror.

Fig. 4. (a) Measured M-XFROG trace around the half rotational revival of O₂. (b) The M-XFROG trace constructed using the probe pulse and the molecular alignment reconstructed by our network. (c) The reconstructed electric field of the probe pulse (solid lines). The dashed lines show the PCGPA results for comparison. (d) The reconstructed molecular alignment factor ⟨cos²θ⟩(t) (solid line) in experiment. The dashed line shows the simulation result based on the experimental parameters for comparison.

Fig. 5. (a) Modulation depth ΔS between the local extremas of the alignment factor as a function of the rotational temperature and pump intensity. The black solid line is a contour line for ΔS = 0.1969. (b) Time interval Δt between the local extremas of the alignment factor as a function of the rotational temperature and pump intensity. The black dotted line is a contour line for Δt = 0.198 ps. (c) Contour lines for ΔS = 0.1969 (solid line) and Δt = 0.198 ps (dotted line). The intersection indicates the molecular rotational temperature and the pump intensity.