Entanglement and quantum correlations in the optical parametric oscillator above threshold
K. N. Cassemiro, Alessandro S. Villar, Paulo Valente, M. Martinelli, P. Nussenzveig · Journal of Physics Conference Series · 2007
We describe several recent experimental studies in the above-threshold optical parametric oscillator (OPO). Seventeen years after the original prediction, entanglement of the twin beams was experimentally demonstrated in 2005. It was followed by the prediction that the OPO should directly produce tripartite pump-signal-idler entangled beams. We also present experimental quantum correlations among these three fields.