Multi-wavelength table top light scattering metrology

Angle resolving light scattering (BRDF) techniques are widely used in the optical industry. Typical applications range from the evaluation of light scattering specifications, over providing input for ray tracing simulations, up to the quantification of the fundamental imperfections that cause scattered light: e.g. roughness, defects, or contamination. Almost all application scenarios benefit from, or even demand for, BRDF measurements at multiple wavelengths. We report on a new generation of the Fraunhofer IOF table top scatterometer AlbatrossTT, which enables BRDF measurement data to be quickly gathered at multiple wavelengths or other parameters such as polarization. Simultaneous BRDF measurements at different illumination wavelengths were realized. This allows different sources of scattered light to be separated, increases the robustness for inverse scattering problems, and provides additional information content. Instrument and concepts are detailed. Applications are presented.