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We have developed fluoride antireflection (AR) coatings on MgF(2) substrates for a wavelength of 248 nm by molecular-beam deposition. Transmission and laser-induced damage threshold of the samples were measured and atomic force microscope (AFM) investigations were carried out. We compare a 14-layer design for AR coatings with sublayer thicknesses of 12 nm with a conventional two-layer design with quarter-wavelength thicknesses. The laser-induced damage threshold of the 14-layer coating is slightly higher than that of the two-layer coating. The AFM surface images show that the 14-layer coating has a smoother surface than the two-layer coating.

The presented work is embedded in the research network "Integrative Ion Processes for Modern Optics", called IntIon, consisting of 12 partners from the German optics industry and two research institutes. The main target of the IntIon network is the development of new process concepts on the basis of ion assisted deposition (IAD) for the industrial production of optical thin film components. Besides an improvement in efficiency, a major aim is concentrated on the optical characteristics for selected application fields with high economical potential. In this network, different ion and plasma sources are compared with regard to their qualification for ion assisted deposition processes. This work includes the characterization of the ion energy and ion current using Faraday-cup measurements. The selection of investigated coating materials includes a broad variety of standard and non-standard oxides. First results of the network will be presented for adapted deposition materials and different operation characteristics of ion sources.

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