Our team runs four cold-atom apparatus based on magneto-optical traps (MOTs). We also have hot vapor experiments. Moreover, we are leading a collaborative project with astronomers and, finally, we have a lot of theoretical activities pursued with many collaborators. See below for more details!
Cold-atom experiment: "Rubidium 1"
Coherence
The experiment Rb1 investigates how light coherence properties and quantum statistics are modified by the interaction with a cold-atom sample. Techniques such as the measurement of the first-order and second-order correlation functions have been developped and applied in a variety of situations.
This setup has a long history, since experiments on random lasing, on MOT dynamic instabilities, on radiation trapping and on coherent backscattering (and a few other stuffs) were done on this setup. This is indeed the first experiment of the team, built in 1997-1998, and still running!
Principal investigator since 2015: Mathilde Hugbart
Cold-atom experiment: "Rubidium 2"
Subradiance
The experiment Rb2 investigates the photonic properties of a 1D ordered atomic sample, by trapping the atoms in a 1D optical lattice. This creates a photonic band gap and a strong Bragg reflection, which can then be used for interesting photonic and quantum optical applications.
Before that and for many years, the experiment was devoted to the study of cooperative scattering of light in disordered and dilute atomic samples. In particular, it has achieved the first observation of superradiance and subradiance in the linear-optics regime.
Principal investigator since 2012: William Guerin
Main current funding: ANR project 1DOrder (2022-2026)
Cold-atom experiment: "Rubidium 3"
Patterns
The experiment Rb3 investigates nonlinear self-organization phenomena induced by the interaction between a retroreflected beam and a cold-atom cloud. Beautiful spontaneous patterns can be created from different kinds of nonlinearities (opto-mechanical,magnetic, etc.).
In the recent past, we have also studied how the light-induced long-range forces determine the static and dynamical properties of MOTs.
A longer time ago, this experiment produced Bose-Einstein condensates and pursued studies on matter-wave dynamics in complex or varying potentials.
Principal investigator : Guillaume Labeyrie
Cold-atom experiment: "Ytterbium"
MOT Yb
The Ytterbium experiment is the newest cold-atom apparatus, whose construction began in 2019 with the ERC grant ANDLICA. It features a blue MOT and a narrow-line green MOT. Experiments are currently done on spatio-temporal properties of the light diffusion within the atomic sample, exploiting the slow timescale of the green transition. The long-term goal is to to achieve strong localization of light in the atoms.
Principal investigators : Raphaël Saint-Jalm & Robin Kaiser
Main current funding: ANR project LoLiA (2024-2028)
Hot vapor experiments: superfluid of light
Hot vapor
The hot vapor experiments are exploiting the nonlinear response of the atoms and the very high optical depth that can be reached by heating up the cells. We study the superfluid behavior of light and investigate how this might be used for potential applications, such as fast optical computation or machine learning.
In the past, we also performed a few experiments on the superdiffusive behavior and the Lévy flights of light undergoing multipe scattering in hot vapors.
Principal investigator : Robin Kaiser
Main current funding: ANR project Wanoo (2024-2027)
Astronomy: Intensity interferometry with modern photonic technologies
Paranal
We are developing new astronomical instrumentation for high angular resolution, based on the intensity correlation between distant telescopes, a technique known as intensity interferometry. We are collaborating with astronomers and astrophysicists from the Observatoire de la Côte d'Azur and testing our instruments on the facilities at Calern, before going to bigger telescopes.
Principal investigators : Robin Kaiser & William Guerin
Main current fundings: ANR project I2C (2021-2025) and ERC project IC4Stars (2025-2029)
Theory: Cooperative scattering and localization of light
Theory localization
Although we are experimentalists, we are also collaborating with many theoreticians and we are regularly publishing theoretical results. The main topics of these studies are cooperative scattering and the localization of light, but we occasionally investigate other things as well.
Principal investigator : Robin Kaiser
Main current funding: ANR project LoLiA (2024-2028)
