Bright entanglement and the Einstein–Podolsky–Rosen paradox with coupled parametric oscillators

We show that two evanescently coupled χ(2) parametric oscillators provide a tunable bright source of quadrature squeezed light, Einstein–Podolsky–Rosen correlations and quantum entanglement. Analysing the system in the above threshold regime, we demonstrate that these properties can be controlled by adjusting the coupling strengths and the cavity detunings. As this can be implemented with integrated optics, it provides a possible route to rugged and stable EPR sources.