Direct Monitoring of Absorption in Solution by Cavity Ring-Down Spectroscopy

Direct monitoring of absorption in solution by cavity ring-down spectroscopy.

Cavity ring-down spectroscopy is applied to the liquid phase by placing the target solution directly into the optical cavity. We demonstrate that solutions in the cavity can be stirred and more importantly monitored in a flow. We report a minimum detectable absorption of 10(-6) cm(-1) for a range of organic solvents. This detection limit corresponds to picomolar concentrations for strong absorb...

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