INTERFERENCE IN LIGHT-SCATTERING FROM SLIGHTLY ROUGH DIELECTRIC LAYERS

The scattering of light from a slightly rough surface overlying a refl ecting surface is investigated. It is shown that the long-scale compon ent of the roughness spectrum plays a critical role in the scattering patterns obtained. The scattered interference patterns are critically dependent on small variation of the rms height of the long-scale compo nent of the roughness. Conventional perturbation theory is found to be invalid in cases in which interference phenomena in the scattering ar e of importance. A model is proposed that quantitatively describes the measured angular intensity distributions. (C) 1998 Optical Society of America.