Selective enhancement of Sel\'enyi rings induced by the cross-correlation between the interfaces of a two-dimensional randomly rough dielectric film

TL;DR

This paper investigates how the cross-correlation between the interfaces of a two-dimensional weakly rough dielectric film affects the selective enhancement of Selényi interference rings in scattered light, using perturbative and non-perturbative solutions of the reduced Rayleigh equation.

Contribution

It introduces a detailed analysis of Selényi interference rings considering interface correlation, revealing how cross-correlation can selectively enhance or suppress specific interference features.

Findings

Selényi rings are observed in diffusely scattered light from weakly rough dielectric films.

Contrast in interference patterns depends on which interface is rough.

Cross-correlation between interfaces can selectively enhance or suppress interference rings.

Abstract

By the use of both perturbative and non-perturbative solutions of the reduced Rayleigh equation, we present a detailed study of the scattering of light from two-dimensional weakly rough dielectric films. It is shown that for several rough film configurations, Sel\'enyi interference rings exist in the diffusely scattered light. For film systems supported by dielectric substrates where only one of the two interfaces of the film is weakly rough and the other planar, Sel\'enyi interference rings are observed at angular positions that can be determined from simple phase arguments. For such single-rough-interface films, we find and explain by a single scattering model that the contrast in the interference patterns is better when the top interface of the film (the interface facing the incident light) is rough than when the bottom interface is rough. When both film interfaces are rough, Sel\'enyi interference rings exist but a potential cross-correlation of the two rough interfaces of the film can be used to selectively enhance some of the interference rings while others are attenuated and might even disappear. This feature may in principle be used in determining the correlation properties of interfaces of films that otherwise would be difficult to access.