Probing optomechanical correlations between two optical beams down to   the quantum level
  Quantum effects of radiation pressure are expected to limit the sensitivity of second-generation gravitational-wave interferometers. Though ubiquitous, such effects are so weak that they haven't been experimentally demonstrated yet. Using a high-finesse optical cavity and a classical intensity noise, we have demonstrated radiation-pressure induced correlations between two optical beams sent into the same moving mirror cavity. Our scheme can be extended down to the quantum level and has applications both in high-sensitivity measurements and in quantum optics. 
P. Verlot (LKB - Jussieu), A. Tavernarakis (LKB - Jussieu), T. Briant   (LKB - Jussieu), P. -F. Cohadon (LKB - Jussieu), A. ...