High performances optical coatings with dual ion beam sputtering technique

Abstract

We present hereafter the results on the manufacturing of complex optical coatings done with dual ion beam sputtering technique (DIBS). Such technology uses a first ion beam gun for sputtering a target and a second one for compacting the sputtered material. The density of the deposited layer is very close to the bulk material and enables the coatings to be nearly insensitive to environmental parameters. This technology is well adapted to severe environments as it allows the production of very dense layers and high quality coatings. The use of an in-situ optical monitoring system in visible and near infrared range (up to 2500nm) permits to reach severe spectral specifications and to have a good agreement with the theoretical designs. In this paper, we will focus on some complex optical functions that have been manufactured with DIBS technique: narrow band-pass filters and wide band filters including large blocking range with more than 100 layers and 25 μm total thickness, antireflection coatings which reach very low values of reflectivity in the near infrared spectral domain for wide angular ranges, and also metal-dielectric absorbing coatings. We will also give an analysis of the cosmetics performances of the deposited layers, which shows the high quality of the coatings even with functions with large total thickness. Many experimental results of qualification tests in temperature, humidity, thermal vacuum, radiations,… are presented and show the reliability of these multidielectric components in space or cryo-vacuum environment.