During the last decade, coating processes have been extended to the reproducible deposition of composite materials on
the basis of simultaneous evaporation or sputtering. Especially, ion beam sputtering from a zone target in conjunction
with sophisticated optical broadband monitoring offers several advantages for the production of oxide coatings with
defined mixture ratios and even Rugate filter systems with a continuous variation of the composition ratio in the depth of
the layer structure. With only two materials on the zone targets, a large dynamic range of refractive index values
covering the indices of the pure materials can be achieved.
Recent studies on the properties of the produced oxide composites indicate a variety of interesting aspects opened by this
new class of material. Among others, a blue shift of the absorption characteristic was observed for ternary oxides, and an
increased LIDT, particularly for sub-picosecond coatings, has been reported. Also a number of investigations of
fundamental damage mechanisms could be carried out by considering the tunable band gap energy of the coating
material. In this endeavor, a group of international collaborators joined in modeling, testing and evaluating the properties
of a variety of ternary oxide systems. A verification of principal material qualities was transferred to applicable multilayer
coatings in a combined effort. In this paper, an overview on the achievements of these current studies is presented
before the background of high power laser applications.