Highly accurate optical material parameter determination with THz time-domain spectroscopy.

We improve the existing data extraction algorithms for THz time-domain spectroscopy (THz TDS) in two aspects. On the one hand, we merge the up-to-date knowledge of THz TDS signal processing into a single powerful optical material parameter extraction algorithm. On the other hand, we introduce a novel iterative algorithm that further enhances the accuracy of the parameter extraction. In contrast to most of the published experiments, we are able to reliably investigate samples with thicknesses as small as 100microm, samples with low indexes of refraction, i.e. close to 1, as well as samples with sharp peaks in the material parameter curves.