Terahertz time-domain spectroscopy of gases, liquids, and solids

Abstract

The techniques and methods employed in the spectroscopic characterization of gases, liquids, and solids in the terahertz frequency range are reviewed. Terahertz time-domain spectroscopy is applied to address a broadband frequency range between 100 GHz and 5 THz with a sub-10 GHz frequency resolution. The unique spectral absorption features measured can be efficiently used in material identification and sensing. Possibilities and limitations of fundamental and industrial applications are discussed.