Optical characterization of an unknown single layer: Institut Fresnel contribution to the Optical Interference Coatings 2004 Topical Meeting Measurement Problem

We present the characterizations performed at the Institut Fresnel for the Measurement Problem of the Optical Interference Coatings 2004 Topical Meeting. A single layer coated on a fused-silica substrate of unknown composition and parameters is analyzed in terms of optogeometrical parameters, uniformity, and scattering. We determine the refractive index and the average thickness of the coating, then provide the localized determination of the thickness with a 2 mm spatial resolution. Topography measurements include atomic force microscopy and angle-resolved scattering measurements. These results are completed thanks to a Taylor Hobson noncontact 3D surface profiler.