Extension of spectroscopic ellipsometry to the far infrared

Abstract The extension of the spectral range of ellipsometry towards the far-infrared region (50–600 cm −1 ) is possible with a combination of two approved methods: Fourier transform spectroscopy and measurements with polarizers at various azimuths. A detailed description of our automatic illuminating set-up which allows easy operation at angles of incidence between 10° and 82°. The design of a suitable prism retarder is shown. Measurements on typical materials in the region of their reststrahlen bands are shown together with simulations. Effects of beam divergence have been taken into account.