Full characterization of bipartite entangled states by means of a single homodyne detector

The authors address the complete experimental characterization of bipartite Gaussian entangled states. Continuous-wave (CW) entangled light beams are generated by a frequency degenerate type-II optical parametric oscillator (OPO) below threshold and their covariance matrix (CM) is fully reconstructed by using a novel scheme that involves a single homodyne detector.