			15min:

HIGH-RESOLUTION FOURIER-TRANSFORM INTRA-CAVITY LASER ABSORPTION SPECTROSCOPY: APPLICATION TO ¹²C₂H₂ NEAR 12300~cm^-1.

SHUI-MING HU, ZHI-YONG WU, YUN DING, AN-WEN LIU, Laboratory of Bond Selective Chemistry, University of Science and Technology of China, Hefei, 230026, China; ALAIN CAMPARGUE, Laboratoire de Spectrométrie Physique (UMR5588), Université Joseph Fourier de Grenoble, BP 87, 38402 Saint Martin d'Héres, France.

The capabilities of ICLAS associated with a high resolution Fourier Transform spectrometer (FT-ICLAS) are investigated with a Ti : Sapphire laser. Weak absorption lines of atmospheric water were used to test the accuracy of absolute intensity measurements by FT-ICLAS leading to an excellent agreement (a few %) with the intensity values obtained by conventional FTS. The performances in terms of spectral resolution (0.028~cm^-1) and sensitivity ( alpha _min~ 2 × 10^-9~cm^-1) are illustrated by the spectroscopic study of the overtone spectrum of ¹²C₂H₂ between 12250 and 12400~cm^-1 which allowed for a significant improvement of recent CRDS measurements. Among the three - Sigma bands rotationally analyzed, one is newly observed. The absolute intensity values of the bands are given.