Our daily lives are now inconceivable without laser and its applications. Whether in the consumer field, in the form of laser scanners at supermarket tills, as the scanning element in CD/DVD/BluRay players or as a laser spirit level, we use the various properties of lasers, in conjunction with modified optical coatings on the lenses and mirrors employed, for our own ends. This is even more the case in the industrial sphere, where lasers perform in measuring devices or are used as production tools for cutting, welding or marking. In this case, optical coatings satisfying the strictest requirements are required. Whether highly reflective, partly reflective or anti-reflective, whether broad-band, narrow-band or with specific filter properties, all such coatings have to be able to withstand high outputs and have high resistance in the long term. High-end qualities can consequently only be achieved using the appropriate high-end process, namely ion-beam sputtering.