The propagation characteristic of the EPR entanglement for a composite non-degenerate parametric optical amplification system

This paper applies the minimum variance V₁ criterion to monitor the evolution of signal and idler modes of a composite non-degenerate optical parametric amplification (NOPA) system. The analytics and numerical calculation show the influence of the transition time, the vacuum fluctuations, and the thermal noise level on the EPR entanglement of the composite NOPA system. It finds that the entanglement and the squeezing degrade as the minimum variance V₁ increases.