40min:
ULTRA SENSITIVE CAVITY RING DOWN SPECTROSCOPY OF MAJOR ATMOSPHERIC SPECIES BETWEEN 1.20 AND 1.71 µm.

A. CAMPARGUE, S. KASSI AND D. MONDELAIN, Université Grenoble 1/CNRS, UMR5588 LIPhy, Grenoble, F-38041, France.

During recent years, we have developed a fibered DFB laser CW-CRDS spectrometer providing routine noise equivalent absorption of alphamin~5×10-11 cm-1, over the 5850-8350 cm-1 range. A detection limit of alphamin~5×10-13 cm-1 has been recently achieved by averaging spectra over a small spectral interval.

The performances of this set up have allowed extending significantly the knowledge of the absorption spectra of molecules of major importance: methane, oxygen, water, ozone, carbon dioxide, hydrogen, nitrogen. The most striking results will be presented.