Advances in IBS Coatings for space applications on the topics of curved surfaces and laser damage

Abstract

IBS Coatings are a good candidate for high performance applications. They are hard, dense, exhibit a small thermal shift, and have the best scattering and surface roughness performance of the various coating technologies. In addition, they feature a highly stable refractive index for the coated materials allowing the production of complex coatings. Because of their high density and resistance towards high energy radiation IBS coatings are also well suited for space applications. For high power laser applications, the vacuum stable damage threshold and low defect concentration qualify especially reactive ion beam sputtering as a suitable deposition method for space applications. In the paper, results on coating activities using the IBS process are discussed in respect to two aspects. One is the adaption of the IBS to strongly curved surfaces like lenses exemplified by the FM lenses for the Copernicus Sentinel-4 mission. The other is a study to increase the laser-induced damage threshold for future LIDAR systems. This is accomplished by eliminating nano-scaled particles that act as damage precursors during laser radiation.

High-Strength Optical Coatings for Single-Crystal ZnGeP2 by the IBS Method Using Selenide and Oxide Materials

“…Ion beam sputtering (IBS) [13] is a deposition method of interference coating with a high LIDT value and dense films with a high-refractive index, which are also characterized by high LIDT values [14][15][16][17]. The IBS method mainly sputters a pure metal target (Ta, Nb, Al, etc.)…”

Annealing‐Induced Changes in the Atomic Structure of Amorphous Silica, Germania, and Tantala Using Accelerated Molecular Dynamics

“…Optical films of the highest quality are often produced by energetic processes like ion‐beam sputtering (IBS) or magnetron sputtering, and the as‐grown films are generally submitted to postdeposition annealing to further improve their optical and mechanical performance. [ 1–5 ] It has been observed that postdeposition annealing of amorphous oxide thin films often reduces the optical absorption at sub‐bandgap energies until the onset of crystallization. Similarly, postdeposition annealing changes the mechanical loss (also known as internal friction) of thin films in a way that depends on the structure of the material.…”