He is "Director of Research" at " National Center for Scientific Research (CNRS)," after having been professor at the Universities of Paris 7 and Grenoble .

He works at Institute of Astrophysics of Paris (IAP), where he was formerly the director. He was earlier director of Observatoire de Grenoble

His past and present fields of research encompass: atomic physics; interstellar molecule; and millimetre radio astronomy; infrared surveys; dust and molecules in extremely distant galaxies, especially around the most distant quasars.