*Ulrike Schulz, Friedrich Rickelt, Kristin Pfeiffer, Adriana Szeghalmi, Fraunhofer Institute for Applied Optics and Precision Engineering IOF, Jena, Germany
Nanostructured layers exhibiting a low refractive index down to 1.1 can be produced fast and easy by physical vapor deposition (PVD) and plasma etching in a commercially available deposition chamber. Combined with interference stacks they can achieve excellent antireflective (AR) properties in a broad spectral range and for high light incidence angles. However, as typical for PVD, thickness gradients occur on the inclined areas of strongly curved lenses and may distract the AR function. In contrast, atomic layer deposition (ALD), which is a comparably slow deposition process, had demonstrated its capability for conformal layer deposition on complicate shaped surfaces. The design developed here combines the advantages of both technologies. The first layer is deposited by ALD with high conformity while all other layers are deposited by PVD. The poster demonstrates the significant improvement of the AR-performance of this hybrid coating on 60° inclines surfaces in comparison to the same coating deposited by PVD only.