Entanglement in quantum-optical bilinear devices
Matteo G. A. Paris · Journal of Optics B Quantum and Semiclassical Optics · 1999
We examine the entanglement arising from the bilinear coupling of two nearly single-mode optical beams. We consider both the case of active and passive linear devices. The two modes are initially prepared in a pair of uncorrelated pure Gaussian states, and the degree of entanglement is analytically evaluated in terms of the excess information entropy at the output. A general formula is obtained and relevant cases are analysed in some detail.