Generation of bright three-color tripartite continuous variable entanglement via the sum-frequency generation

We theoretically show that bright three-color tripartite continuous-variable entanglement can be generated directly by the process of triply resonant sum-frequency generation using a periodically poled supperlattice. It is demonstrated that two reflected pump beams and the output sum frequency beam are all entangled with each other according to the sufficient inseparability criterion for multipartite continuous variable (CV) entanglement. The dependence of the steady state region and the entanglement on system parameters are discussed. By utilizing the up-conversion process, the generated three entanglement fields have macroscopic intensities as soon as the pump fields are turned on.