Optical coatings, i.e. multilayer stacks composed from a certain number
of thin individual layers, are an essential part of any optical system
necessary to tailor the properties of the optical surfaces. Hereby, the
performance of any optical coating is defined by a well-balanced
interplay between the properties of the individual coating materials and
the geometrical parameters (such as film thickness) which define their
arrangement. In all scientific books dealing with the performance of
optical coatings, the main focus is on optimizing the geometrical
coating parameters, particularly the number of individual layers and
their thickness. At the same time, much less attention is paid to
another degree of freedom in coating design, namely the possibility to
tailor optical material properties to an optimum relevant for the
required specification. This book, on the contrary, concentrates on the
material aside of the problem. After a comprehensive review of the
basics of thin film theory, traditional optical coating material
properties and their relation to the efficiency of coating design
methods, emphasis is placed on novel results concerning the application
of material mixtures and nanostructured coatings in optical coating
theory and practice, including porous layers, dielectric mixtures as
well as metal island films for different applications.