INTRACAVITY LASER ABSORPTION SPECTROSCOPY - A COMPARISON WITH CLASSICAL ABSORPTION - LINE SHAPES AND QUANTITATIVE MEASUREMENTS

Author Institution: Laboratoire de Spectrometrie Physique Universite Scientifique et M\'edicale de Grenoble - BP68 38402, Saint Martin d'H\'eresUsing a CW dye laser for intracavity laser absorption spectroscopy (ICLAS) with a controlled time generation and a time-resolved spectrum, we show that intracavity absorption follows the Lambert Beer Law. By comparing the absorption of the very weak $\gamma$ band of $O_{2} b^{1}\Sigma_{g}^{+}(v^{\prime}=2)\leftarrow X^{3}\Sigma_{g}^{-}(v^{\prime\prime}=0)$ in ICLAS and in multi-pass cell $technique^{1}$ we confirm that the intracavity technique gives reproducible results under different experimental conditions and is a highly sensitive quantitative method for measuring absolute absorption coefficients and collision broadening coefficients. This method does not necessitate any previous scaling in contrast with other sensitive methods like photo-acoustic or optogalvonic techniques. $^{1}$J. J. Miller, L. P. Giver, R. W. Boese, J.Q.S.R.T. 16 (1976) 595