The possibility of determining interface roughness and cross-correlation statistics of the two interfaces of a thin film from angle-resolved light scattering data at three wavelengths is investigated. It is shown that angle-resolved light scattering measurements at three wavelengths are not sufficient to determine the three power spectral density functions describing the thin film roughness. An attempt to combine reflectance and transmittance scattering to determine the roughness of a thin film on a transparent substrate appears to work and provides encouraging results.
Daniel Roennow, Daniel Roennow,
"Interface roughness statistics of thin films from angle resolved light scattering at three wavelengths," Optical Engineering 37(2), (1 February 1998). https://doi.org/10.1117/1.601870