A key to improving the performance of high quality optics, and in particular the thin film coatings on the optics, is to reduce scattering and absorption losses, especially caused by roughness at interfaces. In this paper are discussed the origins of scattered light, scalar and vector theories to predict scattering from surface microirregularities, and methods for measuring hemispherical and angle-resolved scattering. In addition, ways of measuring surface microstructure and defects, and bulk and interface absorption in films and substrates are also described.
by Jean M. Bennett