High sensitivity intracavity absorption spectroscopy of CHD 3 in the near infrared with a titanium:sapphire laser

Abstract

By using a Ti: sapphire crystal as an amplifying medium the intracavity laser absorption spectroscopy technique (ICLAS) has been extended to the near-infrared range (10000–12000 cm −1 ). This range of energy is particularly interesting for the overtone spectroscopy of XH stretching vibrations (XC, N, O, Si, Ge). As an illustration of the possible spectroscopic applications of this spectrometer we present here the absorption spectrum of CHD 3 in the range of the Δν CH = 4 overtone transitions. Due to the Fermi interaction between the ν 1 stretching mode and the ν 5 bending mode, two bands have been observed at 11266.95 and 11062.6 cm −1. Their rotational analysis is reported and discussed.