Optical Properties of Materials in the Terahertz Spectral Range

Kałuża, M., Komorowski, P., Walczakowski, M., Nieradka, A. and Siemion, A.

Abstract

The study presents a database of optical properties for a wide range of materials within the terahertz (THz) radiation range. The analysis focused on the absorption coefficient and refractive index in the frequency domain in the range from 100 GHz to 1 THz. A total of 99 materials were analyzed using THz time-domain spectroscopy (THz-TDS), including 56 types of polymers and composites commonly used in additive manufacturing technologies such as fused deposition modeling (FDM) and selective laser sintering (SLS), as well as 43 casting materials such as waxes, clays, soaps, and chocolates. Measurements were performed with the TPS 3000 spectrometer (TeraView) spectrometer in a dry-air chamber on cylindrical samples with a thickness of 4 mm and a diameter of 13 mm. Additionally, absorption coefficient measurements for six transparent polymer materials were conducted over a broad spectral range from 0.1 THz to 200 THz. The data were obtained by combining THz-TDS measurements with two Fourier Transform Infrared Spectroscopy (FTIR) measurement ranges: the first spanning 2–20.4 THz and the second covering 12–200 THz, using the FTIR TermoScientific Nicolet 6700 and FTIR Bruker VERTEX 80v spectrometers.

Full paper can be viewed here.