High Resolution Dispersive Fourier Transform Spectroscopy for Pollutant Gases at Millimeter Wave and Terahertz Frequencies

Dispersive Fourier transform spectroscopy (DFTS) provides us with a very precise method of measuring the absorption and refractive index spectra of pollutant gases. This paper presents the rotational transition lines of sulfur dioxide gas as a function of varying pressure using DFTS for the very first time. The relationship between the variation of the pressure and the change in the absorption spectrum is examined and discussed in detail. Sulfur dioxide gas is a highly toxic, pollutant gas that contributes to global pollution and can potentially be used as a chemical threat. These findings, presented from 0.3 THz - 0.9 THz, are therefore of great importance in studying air pollution and identifying gases in a blind test.