Anti-reflection coatings based on quantized nanolaminates manufactured by ion beam sputtering

All naturally occurring materials show a fixed combination of refractive index and bandgap energy, which correlates with their absorption. Both properties are material constants. Metamaterials are an alternative approach to vary these constants independently and increase the transparency range of existing optics in the UV. These metamaterials can be produced using quantum nanolaminates (QNLs). The special type of material sequence in the QNLs coatings opens up a wide range of possible material parameters without the process problems which occur with mixed materials that are commonly used in this context. This presentation is going to investigate the concept of nanolaminates made from the high-refractive index material hafnia (HfO2) and the low-refractive index material silica (SiO2). In order to reach a blue shift of the absorption edge, the QNLs were applied in an anti-reflex coating as a substitute for the high-refractive coating material. All layers were produced by ion beam sputtering.