Entanglement of fields in coupled cavities: Effects of pumping and fluctuations

A system of two coupled cavities is studied in the context of bipartite, continuous variable entanglement. One of the cavities is pumped by an external classical source that is coupled quadratically, to the cavity field. Dynamics of entanglement, quantified by covariance measure [V.V. Dodonov, et al., Phys. Lett. A 296 (2002) 73], in the presence of cavity–cavity coupling and external pumping is investigated. The importance of tailoring the coupling between the cavities is brought out by studying the effects of pump fluctuations on the entanglement.