Resolution:
## Figure 1.
Sketch of the structure used to model the ellipsometric data. Left: schematic drawing of the NAA structure showing the pores, the alumina, and
the aluminum substrate. Right: the corresponding layered optical model considered
by the characterization software. P is the porosity of the NAA, which corresponds to the volume fraction of air. The
plus sign represents the use of a Bruggeman effective medium approximation to model
the refractive index of the mixture of materials in the layer.
Rahman |