Phase shift cavity ring down absorption spectroscopy

Phase shift cavity ring down absorption spectroscopy

Cavity ring down absorption spectroscopy with a continuous light souree is used to measure the transition frequencies and absolute absorption coefficient of the weak b ItCv' = 2) +--X I;-Cv" = 0) transition of 02. The absorption spectrum is extracted from a measurement of the magnitude of the phase shift that an intensity modulated continuous light beam experiences upon passing through an unsta...

Saturated-absorption cavity ring-down spectroscopy.

We report on a novel approach to cavity ring-down spectroscopy with the sample gas in saturated-absorption regime. This technique allows us to decouple and simultaneously retrieve the empty-cavity background and absorption signal, by means of a theoretical model that we developed and tested. The high sensitivity and frequency precision for spectroscopic applications are exploited to measure, fo...

Cavity ring-down spectroscopy for quantitative absorption measurements

We examine under what conditions cavity ring-down spectroscopy ~CRDS! can be used for quantitative diagnostics of molecular species. We show that CRDS is appropriate for diagnostics of species whose absorption features are wider than the spacing between longitudinal modes of the optical cavity. For these species, the absorption coefficient can be measured by CRDS without a knowledge of the puls...

Cavity-locked ring-down spectroscopy

Derivation of new equations for phase-shift cavity ring-down spectroscopy.

Current phase-shift cavity ring-down spectroscopy (PS-CRDS) experiments make use of equations originally developed for fluorescence studies. As these equations fail to take the length of the optical cavity and the superposition of reflecting beams into account, they lose validity as the length of the cavity increases. A new set of equations, based solely on the principles of PS-CRDS, is develop...