Properties of optical film materials

In the first part of the paper some basic considerations in the choice of optical film materials are discussed, in particular, the chemical stability of the material in the evaporation or sputtering process and the desired optical and physical properties. In the second part the dependence of some important film properties on deposition conditions is reviewed, and the state of the art is demonstrated for a number of examples. The paper concludes with a few remarks on the problems in research and development in this field.