Probing atoms and molecules close to macroscopic bodies

In this habilitation thesis, I briefly present my work at Imperial College London on trapping atomic clouds in micro-pyramids fabricated on silicon chips, which led to the fabrication of an on-chip integrated atom source. Next, I describe the research carried out at the Laboratoire de Physique des Lasers in the SAI group. Our experiments demonstrated the temperature dependence of near-field Casimir-Polder interactions due to thermal excitation of surface waves, thus advancing our understanding of the dielectric properties of matter and the quantum vacuum that surrounds it. I also present spectroscopic experiments with atomic vapors confined in nanostructures (nano-sphere opals) aiming at the fabrication of miniature frequency references. Finally, I explore the possibility of performing spectroscopic experiments on molecular gases close to surfaces.