OPTICAL SCATTERING IN MULTILAYER THIN-FILMS

The matrix formulation of the theory of the optical properties of multilayer thin films is extended by the inclusion of appropriate scattering coefficients to account for the effects of interfacial roughness, particularly the spatial and spectral distributions of scattered radiation. The relationships of the generalized theory to well-established principles and theorems of thin film optics is emphasized, and the results are used to explain the characteristics of the radiation scattered by all-dielectric interference filters. To obtain quantitative predictions, relationships are also derived between interfacial scattering coefficients and the structural parameters of the rough interfaces between layers. Two approaches are used, one involving perturbation radiation from interfacial electric dipoles and the other the Kirchhoff vector diffraction integral, and the values of the resulting scattering coefficients are compared. © 1979 Taylor & Francis Group, LLC.