Scattering by randomly rough dielectric surfaces and rough dielectric films: influence of the height distribution

Scattering of electromagnetic waves by randomly rough surfaces can be model led efficiently by perturbation theory if the root mean square (rms) height is smaller than 0.061. In this regime, the angular scattering pattern depe nds strongly on the correlation length a. It will be shown that for penetra ble media, the height distribution strongly influences the angular scatteri ng pattern. This property is illustrated with two different systems: a rand omly rough dielectric surface and a rough dielectric film deposited on a pe rfectly conducting substrate. A model recently introduced (mean-field theor y) yields a physical explanation of this behaviour. This approach is used t o analyse the fringes produced by a randomly rough dielectric film deposite d on a flat reflecting susbtrate. It is shown that the features of the frin ges can be explained when accounting for the height distribution.