Multi-colour entanglement directly generated by the enhanced Raman scattering

Abstract

Multi-colour continuous-variable frequency comb entanglement can be directly generated by enhanced Raman scattering in a hexagonally-poled LiTaO 3 optical superlattice. Raman scattering signals are distinctly boosted by a coupled quasi-phase-matching optical parametric amplification process which has been realized in a previous experiment (Xu et al 2005 Phys. Rev. B 72 064307). The conversion dynamics of the coupled optical parametric amplification process is investigated here using quantum stochastic methodology, and the nature of entanglement among the Raman signals is discussed by applying a necessary and sufficient continuous variable criterion. Multi-colour entanglement with the same frequency interval can be obtained directly, with no optical oscillator cavity, in the enhanced Raman scattering process; this has potential application in quantum communication and computation networks.

Five-partite continuous-variable entanglement generated by cascaded nonlinear processes in only one optical superlattice

“…Cascaded optical parametric amplifiers with low pump parameter can generate bandwidth multipartite entanglement fields [32]. A multi-colour entanglement frequency comb can be produced by an enhanced Raman scattering process with optical cavities [33] and without optical cavities [34]. Quadripartite entangled beams can be generated by intracavity down-conversion cascaded two sum-frequency processes [35].…”