INTRACAVITY LASER ABSORPTION SPECTROSCOPY IN THE NEAR INFRARED WITH DOPPLER LIMITED RESOLUTION.

Author Institution: Institute for Spectroscopy; Institute of Physical Chemistry, University of Goettingen; Laboratoire de Spectrom\'{e}trie Physique, Universit\'e Joseph Fourier de Grenoble/CNRS URAIntracavity laser spectroscopy (ICLAS), since its introduction in early $70^{th}$, has been considered by most of the spectroscopists as an extremely sensitive, but rather complicated technique with many nonlinearities involved. We intend to show that it is neither complicated, nor nonlinear. The performance of a solid-state intracavity laser spectrometer for the study of highly excited vibrational states of both stable and unstable species as well as for time-resolved studies of chemical reactions on the sensitivity limit up to $10^{-13} cm^{-1}$ will be demonstrated. For analytical applications the IR ICLAS promises to be more versatile, less complicated, less expensive and up to three orders of magnitude more sensitive than frequency modulated diode laser spectrometers. A comparative analysis of the ICLAS and other highly sensitive methods of measuring absorption spectra will be made