Figure 4.

GISAXS signals and corresponding retrieved real-space electron density profile. (a) Lineout at $0 \mathrm{p}\mathrm{s}$ (white circular dots) and $1 \mathrm{p}\mathrm{s}$ (grey circular dots) after the laser intensity peak. Solid lines represent models using the program BornAgain (https://bornagainproject.org/). (b) Zoom into the area of the Bragg-like peak at $Q_z=2.1 \mathrm{n}{\mathrm{m}}^{-1}$ and (c) zoom into the area of dynamical diffraction around $Q_z=0.75 \mathrm{n}{\mathrm{m}}^{-1}$. (d) Retrieved real-space effective electron density profile as a function of the depth (Z). The laser irradiates the sample from the left. (e) Generated surface model for $H=0.6$, $\sigma =2.3 \mathrm{n}\mathrm{m}$ and (f) $H=0.15$, $\sigma =2.6 \mathrm{n}\mathrm{m}$. (g) Lineout along $Q_y$ at the Al Yoneda peak ($Q_z=0.75 \mathrm{n}{\mathrm{m}}^{-1}$). Dashed lines indicate a fit of the decay. (h) Lineout along $Q_y$ at $Q_z=2.1 \mathrm{n}{\mathrm{m}}^{-1}$.