Relation between light scattering and the microstructure of optical thin films

Abstract

Special substrate-film designs are used to measure roughness-induced scattering and scattering from the volume of optical thin films separately. So theoretical models of surface roughness and volume scattering become applicable to the experimental data, and quantitative information on thin-film microstructure can be derived. Measuring total integrated and angle-resolved scattering on oxide, fluoride, and chalcogenide films of different film thicknesses yields the evolution law of microstructural growth, which for the majority of investigated films roughly follows a square-root dependence on film thickness. Packing densities of fluoride films calculated from volume-scattering data are found to agree with results from quartz-crystal monitoring.

Shape and surface texture of molten droplets deposited on cold surfaces

“…In our tests, we observe that different surface textures can be formed on the surface of ink droplets when the droplets impact and solidify on solid surfaces under varied conditions. The surface texture can alter the optical properties of materials, such as light scattering [17], optical absorptivity [18] and transmittance [19]. In addition to optical properties, the surface texture affects the mechanical properties of deposited materials.…”

Reducing light scattering from surface contaminations by thin film design

“…These theories were experimentally verified to be very accurate [1,[12][13][14], but are limited to smooth surfaces with σ  λ (which, in fact, holds for the vast majority of optical coatings). In contrast to single surface scattering, predicting light scattering from multilayer coatings is more complex as interference effects have to be considered [15][16][17]. The ARS of a thin film stack of N layers is given by Ref.…”

Reflectance and transmittance model for multilayer optical coatings with roughness at oblique incidence

“…In this multilayer structure, the roughness on surfaces and interfaces might not only change the specular properties of layers, such as reflectance and transmittance, but also produce diffuse scattering [11][12][13]. Therefore, we must also consider the possible influence of scattering to multilayer system, and this will be discussed in Section 2.2.…”