The “Quantum Optics and Quantum Information” research topic brings together 4 research groups dealing with different aspects of the foundations of quantum theory and quantum fluctuations. Among the numerous research subjects, one should mention Quantum Non Demolition measurements, entanglement and decoherence, the generation of non-classical states, quantum limits in high-sensitivity measurements, quantum memories and other quantum information devices, the Casimir force or the link between quantum fluctuations and relativity. These research are performed with a number of experimental systems: Rydberg atoms coupled to microwave fields, cold atoms, atom chips, microcavities, optical parametric oscillators, and micro- and nanomechanical resonators coupled either to quantum vacuum or to intense laser fields.