Direct laser writing of optical gratings on additive manufactured metal surfaces

Abstract

Enhancing the functionality of surfaces has increasingly become the focus of modern engineering in recent years. Functional material surfaces can be developed through targeted micro structuring. For example, surface modifications by micro structuring can change the wetting behaviour or effectively optimize the frictional properties. Some of these applications are already established on the market and e.g. used in case of improving highly stressed surfaces. To accelerate further research in this direction, the present work deals with the functionalization of surfaces with the aim of modifying optical properties. The overall vision for this is the production of functional enhanced additive manufactured free-form mirrors for technical applications. Nowadays, the additive manufactured metal mirrors need a complicated and time-consuming mechanical post-processing like e.g. manual polishing. To add a further functionalization, structures like e.g. optical gratings need a separate production step, mostly limited to one fix structure geometry and size. Thus, laser direct writing as an alternative method and highly flexible production process is examined.