  Terahertz time-domain spectroscopy (THz TDS) is a well-known tool for
material analysis in the terahertz frequency band. One crucial system component
in every time-domain spectrometer is the delay line which is necessary to
accomplish the sampling of the electric field over time. Despite the fact that
most of the uncertainty sources in TDS have been discussed, the delay line
uncertainty has not been considered in detail. We model the impact of delay
line uncertainty on the acquired THz TDS data. Interferometric measurements of
the delay line precision and THz time-domain data are used to validate the
theoretical model.

Optics;Applied Physics;Data Analysis, Statistics and Probability;Instrumentation and Detectors