Measurement comparison among Time-Domain, FTIR and VNA-based spectrometers in the THz frequency range

TL;DR

This study compares three types of terahertz spectrometers—FTIR, VNA, and Time-Domain—in terms of measurement capability and uncertainty, providing insights into their performance for dielectric material analysis.

Contribution

First international comparison of THz spectrometers across different technologies, evaluating their measurement capabilities and uncertainties.

Findings

FTIR, VNA, and Time-Domain spectrometers show comparable measurement accuracy.

Differences in measurement uncertainty highlight the strengths and limitations of each spectrometer type.

Results inform best practices for THz spectrometry in dielectric material characterization.

Abstract

In this paper we present the outcome of the first international comparison in the terahertz frequency range among three different kinds of spectrometers. A Fourier-Transform infrared spectrometer, a Vector Network Analyzer and a Time-Domain Spectrometer have been employed for measuring the complex refractive index of three travelling standards made of selected dielectric materials in order to offer a wide enough range of parameters to be measured. The three spectrometers have been compared in terms of measurement capability and uncertainty.