Angular Selective Window Coatings: Theory And Experiment

Publisher Website
Google Scholar
Abstract
Surface coatings with strongly angular-dependent transmittance are explored theoretically and experimentally. Theoretical studies are reported for multilayer coatings with more than one uniform metal film and for single-layer coatings with oblique columnar microstructure. The latter coatings are represented by effective medium theories encompassing prolate spheroidal structure elements. Amplitude coefficients for transmission and reflection are derived for the plane spanned by the column axis and the surface normal in uniaxial materials; these coefficients are extensions of well-known Fresnel relations. The transmittance of p-polarized light is angular selective, i.e. is unsymmetric around the surface normal, for absorbing columns. An experimental study of obliquely evaporated metal films showed that well defined inclined columns could be observed in scanning electron micrographs of fractured Cr films, and that the optical properties of such films displayed angular selectivity in qualitative agreement with theory.

This publication has 0 references indexed in Scilit: