ABSTRACT
This chapter provides basic guidelines for the design, manufacture, testing, and use of high damage threshold laser coatings. It provides guidelines for the choice of deposition methods, materials, and coating designs that yield state-of-the-art coatings for high-power laser applications. Optical coatings have additional anisotropic and discontinuous properties. These properties include densities which are typically down that of their bulk counterparts, thickness-dependent crystal structures and optical properties, high densities of electronic and structural defects, and film interfaces which affect mechanical and optical properties. Inorganic oxides or fluorides remain the predominent materials used for laser coatings and so far very little use has been made of organic polymer coatings even though many have excellent properties for other coating applications. There are, however, certain exceptions and recently some useful laser coatings have been prepared from organic polymers. Two main areas have been investigated: quarter-wave AR coatings and protective layers on environmentally sensitive optical components, or on soft, easily abraded porous silica AR coatings.
