Bright three-color continuous-variable entanglement produced by quasi-phase-matched third-harmonic generation

We presented a scheme to produce bright three-color continuous-variable (CV) entanglement by cascaded quasi-phase matched sum-frequency processes. Second and third-harmonic fields are generated by two sum-frequency processes,respectively. The fundamental, second-, and third-harmonic fields are CV entangled with each other by applying the necessary and sufficient CV entanglement criterion. The relations between the entanglement features of the three beams and nonlinear coupling parameters and damping rates are also discussed.