Figure 4.

XZ cross sections of the Ga atomic density at depths Y = 0 μm (a) and Y = 3.25 μm (b). XZ cross sections of the Br atomic density at Y = 6.75 μm (c) and Y = 9.85 μm (d). The scale bars represent 2 μm; the intensity bars, the number of atoms per voxel (with volume 50³ nm³). White dashed lines delineate the crystal’s cross section and the external surface. (e) Number of bromine atoms per slice integrated along Z, as a function of Y. The lattice parameter a of the photonic crystal is shown. The periodicity of the pores is clearly visible. Red circles indicate the Y coordinates in c and d.