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Optical digital tomographic microscopy can be used for profilometry. The profile of the surface can be estimated from measurements of the complex diffracted far field obtained when the sample is illuminated successively under various incidences. Outside the validity domain of perturbative theories of diffraction, the profile is determined by using an iterative inverse wave scattering numerical method. In this paper we show that, for perfectly conducting surfaces, the two fundamental polarization cases involve different distances of interaction in the multiple scattering phenomenon. The use of both polarization cases in the inversion process leads to a considerable improvement of the lateral resolution. Robustness to noise is also discussed.

We show that tomographic diffractive microscopy can be used for profilometry applications with high transverse resolution. We present an iterative reconstruction procedure, based on a rigorous wave scattering model, that permits us to retrieve the profile of rough metallic interfaces from the complex scattered field. The transversal resolution is subwavelength, and can even fall below the classical resolution limit if the profile is rough enough for multiple interactions to occur. Large profiles, with tens of wavelength size, can be investigated.

The intensity scattered by particles randomly placed beneath a rough interface is studied with rigorous simulations. It is shown that the angular intensity pattern is close to that obtained by adding the intensity scattered by particles under a flat surface to that scattered by a rough homogeneous surface whose permittivity is evaluated with an effective-medium theory. This heuristic splitting rule is accurate for a large range of parameters that are well beyond any perturbative treatment.

We adapt the differential method to the study of scattering from randomly rough inhomogeneous films, and we extend the application domain of the surface-integral method to rough surfaces with many embedded scatterers. These methods are compared in the case of geometries in which both volume and surface scattering occur. A good agreement is obtained, and the advantages and drawbacks of each technique are pointed out. The angular scattering from rough inhomogeneous structures corresponding to models of snowcover in the radio-frequency domain or paints in the optical domain is shown.