UFR de Physique

Propositions de stages en laboratoire -- M2

Les offres sont actualisées en mai. Par exemple, les offres de stages pour l'année universitaire 2015-2016 seront mises en place en mai 2015, les offres de stages pour l'année universitaire 2016-2017 seront mises en place pour en mai 2016, etc.

Acquisition and Modelling of NICE-OHMS signals of prototype Molecules

  • Option Lumière-Matière, Générique du parcours Lumière-Matière
  • Laboratoire: Laboratoire de Physico-Chimie de l'Atmosphère (LPCA)
  • Responsable du stage: DUPRE Patrick (patrick.dupre@univ-littoral.fr,
  • Mots clés: Cavité à haute finesse, Absorption saturée, NICE-OHMS.
  • Fiche complète en PDF : Fiche complète en PDF

The detection of weakly absorbing molecular species is a contemporary challenge for the gas spectroscopy. We face such challenges when the species of interest (molecules, radicals, ions) exhibit weak absorption crossections, and/or when the species are only available under weak number density. Hence, we need to develop very sensitive spectroscopy instruments. To maximize the signal-to-nose ratio, we are implementing the Noise-Immune Cavity-Enhanced Optical Heterodyne Molecular Spectrometry technique. It is an ultimate technique because the quantum photon shot-noise limit can be challenged. It combines a high-finesse cavity, to increase the absorption path length, and a phase modulation (FMS) to wash out the laser source intensity fluctuations. This technique has been pioneerly developed at NIST in the late 1990s by J. Hall (Nobel prize), and it is has been disseminated only in a few laboratories in the world. The Near-InfraRed and Mid-Infrared are the 2 frequency ranges targeted in the lab. This first range benefits of the recent developments due to the telecom industry. The latter range offers a reach potential for the molecular detection (not implemented yet). According to, the current status of the project, the proficiency and the wishes of the student, several experimental and/or modeling tasks will be considered. However, we anticipate that highly saturated NICE-OHMS spectra may exhibit new behavior on simple molecular system. Opportunities will be given to a self-motivated student who will have a unique opportunity to develop his own proficiency in state-of-the-art instrumentation as well as in a challenging field of research.