Thin Solid Films, Vol.592, 248-255, 2015
Origins of light scattering from thin film coatings
The light scattering properties of multilayer coatings is substantially more complex than that of single surfaces. Yet new experimental methods and modeling techniques enable multilayer scattering to be investigated and analyzed in detail. In this article, the dominating factors influencing the scattering of near infrared suppressing interference filters are discussed. This is done by combining angle resolved light scattering measurements at different wavelengths with roughness metrology and simplified theoretical models. The impact of different sources of scattering, in particular substrate and coating roughness, interference effects, and local defects, are discussed in a quantitative manner. It will be demonstrated that the impact of nodular defects is negligible while the impact of interference effects is not. (C) 2015 Elsevier B.V. All rights reserved.