Classification of terahertz spectrometer for transmittance measurements of refractive materials

: A comparison between commercially available transmission terahertz spectroscopy systems using photoconductive antennas owned by three participating institutions was performed to verify the effects of the speci fi cations of each system on the transmittance measurement uncertainty. Three types of sample with different compositions and shapes were circulated around the participating institutions, and the data obtained from their systems were compared. We veri fi ed that sample thickness and its non-parallelism affected measurement data by carrying out measurements and calculations. On the basis of the components of variations in the measurement data, we tried to classify the fi ve measurement data sets. The results indicated that the system users can easily compare their measurement conditions with those of other systems using statistical analysis.