In this paper, we show how thin film multilayer coatings can be a solution to answer this problematic as it is possible to design accurate spectral response that presents a very low level of reflectance with a zero value of transmittance.
After a description of the design steps, we will focus on the realization of such sophisticated metal-dielectric multilayer stacks using dense coating techniques; in particular, we will show that master of refractive index of very thin metallic layers is an asset to achieve accurate performances and how in situ optical broadband monitoring allows excellent reproducibility of production processes even for few nanometers-thick layers required in metal-dielectric absorbers.
Spectral and angular measurements of different coatings solutions will be given on various types of substrates (glass or metallic). Environmental qualification tests and spectral characterizations are also presented showing the stability of the performances in severe conditions compatible with severe environment. In particular, coatings developed for various projects will illustrate this study.