Coline Mahob

Ozone is a key molecule in atmospheric composition and climate change, and its accurate measurement is essential for monitoring ozone layer recovery and assessing its impact, particularly in the upper troposphere–lower stratosphere (UTLS) region. This thesis aims to improve ozone spectroscopic data in the 306–320 nm wavelength range through high-precision, temperature-dependent measurements based on advanced laser techniques.

A new experimental setup will be developed using tunable UV laser sources based on nonlinear optics. These sources will provide narrow-linewidth, monochromatic radiation. Combined with a vacuum system for ozone trapping, the setup will enable absolute absorption cross-section measurements with sub-percent accuracy. The resulting data will contribute to the improvement of spectroscopic databases and to a more accurate quantification of atmospheric ozone and its long-term evolution.