The Kastler–Brossel Laboratory, located in Paris, France, is a research laboratory specializing in fundamental physics of quantum systems. Founded in 1951 by Alfred Kastler and Jean Brossel, it is a joint research unit operated by the French National Centre for Scientific Research (CNRS), the École normale supérieure, the Pierre-and-Marie-Curie University and the Collège de France.
Many new themes have appeared recently in the field of fundamental physics of quantum systems, like quantum entanglement or Bose-Einstein Condensation in gases, which leads to a constant renewal of the research carried out in the laboratory. Presently its activity takes several forms: cold atoms (bosonic and fermionics systems), atom lasers, quantum fluids, atoms in solid helium; quantum optics, cavity quantum electrodynamics; quantum information and quantum theory of measurement; quantum chaos; high-precision measurements. These themes lead not only to a better understanding of fundamental phenomena, but also to important applications, like more precise atomic clocks, improvement of detectors based on atomic interferometry or new methods for biomedical imaging.