Terahertz Time-Domain Spectroscopy of Organic Gases

Abstract

We identify gases using terahertz time-domain spectroscopy (THz-TDS) in order to realize a short-range THz-Lidar. As the first step, pure rotational spectra of three organic gases (methanol, acetone and ethanol) were each measured by THz-TDS. THz waves are both generated and detected by photoconductive antenna. The frequency range of our THz system is from 0.1 to about 3 THz. According to our experimental results, we found strong absorptions caused by methanol gas and acetone gas, while ethanol gas showed no obvious absorption.