Self-broadening in the fundamental bands of HF and HCl

Abstract

Self-broadened lineshapes in the fundamental bands of HF and HCl have been measured with a high-resolution difference-frequency laser spectrometer. Self-induced broadenings, shifts, and collisional narrowings have been extracted by least-squares fitting several collisional profiles to the spectra. At low pressures, the collisional narrowing effect causes deviations of the lineshapes from the Voigt profile having a Doppler-fixed Gaussian component, and yields a measure of the diffusion constants of the molecules.