Polarisation-dependent IR spectroscopy and ellipsometry is particularly well suited to examining new materials, metamaterials, hybrid materials and thin organic and inorganic layers from just a few micrometres thickness through to a monolayer. It enables optical constants and layer thickness to be determined and delivers detailed information on matters such as the chemical structure and molecule orientations in polymers, the doping properties of conductive polymer films or the dielectric function of graphene. We are currently investigating modification and growth at the solid-liquid interface in particular, although we also make microscopic measurements, above all on functional films and surfaces and on layers consisting of polymers and proteins.