FIR laser assignments and frequency predictions for optically pumped13CD3OH by high-resolution Fourier transform spectroscopy

Abstract

Continued study of the high-resolution Fourier transform spectroscopy (FTS) of the fundamental CO-stretching band of13CD3OH has given additional insight into the far-infrared (FIR) laser emission observed when this molecule is optically pumped by a CO2 laser. Eleven IR-pump/FIR-laser transition systems are considered. Seven represent completely new assignments, while four have been presented previously but are discussed further with reference to recently reported experimental data. Ten of the assignment schemes have been rigorously checked by forming closed combination loops, and accurate FIR laser wavenumbers have been obtained. The superiority in precision of the FIR laser wavenumbers determined from FTS combination loops over those from traditional wavelength measurements is demonstrated.