Three-mode entanglement by interlinked nonlinear interactions in optical chi((2)) media

We address the generation of fully inseparable three-mode entangled states of radiation by interlinked nonlinear interactions in chi((2)) media. We show how three-mode entanglement can be used to realize symmetric and asymmetric telecloning machines, which achieve optimal fidelity for coherent states. An experimental implementation involving a single nonlinear crystal in which the two interactions take place simultaneously is suggested. Preliminary experimental results showing the feasibility and the effectiveness of the interaction scheme with a seeded crystal are also presented. (C) 2004 Optical Society of America.