Line Strengths and Self-Broadening of Pure Rotational Lines of Carbon Monoxide and Nitrous Oxide Measured by Terahertz Time-Domain Spectroscopy.

Terahertz time-domain spectroscopy was used to obtain the line intensities and selfbroadening parameters of pure rotational lines of CO and N2O. The technique yields a direct measurement of an absorption spectrum from 0:2 THz to 3 THz, which is linear in amplitude, therefore allowing the profiles of multiple lines to be observed and quantified. The transitions studied in CO were from J′ = 3 <- 2 to J′ = 22 <- 21, and in N2O from J′ = 9 <- 8 to J′ = 52 <- 51. The gas spectra were measured at elevated pressures in the range of 0:7-5 bar for CO and 0:7-1:7 bar for N2O. The measured absorption spectra were analyzed assuming a Lorentzian lineshape and using a multiple-peak fitting procedure. The obtained values of the line intensities and self-broadening parameters are in good agreement with the HITRAN database.