Laboratoire Interdisciplinaire de Physique

Electric-quadrupole infrared transitions are detected in water vapor at room temperature. This is the first direct detection of quadrupole transitions in a polyatomic molecule. Using a newly developed, high-accuracy variational approach for theoretical predictions, several weak quadrupole transitions of H2O were identified in a highly sensitive cavity-ring-down spectrum of water vapour near 1.3 µm, in full agreement with the computational predictions.

FRET, Förster Resonance Energy Transfer, is an energy transfer between two fluorophores that only takes place when they are within 10nm of each other. The quantitative measurement of this effect makes it possible to measure distances in the nanometer range with a simple fluorescence microscope. While this was possible for isolated molecules, quantification of FRET was considered almost impossible in more complex samples. A team at LIPhy has developed a new method for quantitative measurements of FRET in living cells. This paves the way for a more extensive and successful use of fluorescent biosensors.

Air bubbles in water are excellent resonators under acoustic frequencies. They are an avenue for new underwater acoustic materials, provided they are stabilized over time and their spatial position is controlled. Using 3D printed supports, physicists from Grenoble have demonstrated that it is possible to generate "faceted bubbles", which are more durable and efficient than conventional spherical bubbles.