Multicolored multipartite entanglement is of great importance in quantum communication and quantum information networks. In this paper, we calculate the quantum fluctuations of the fundamental frequency pump beam and second-harmonic beams in a two-port frequency doubling resonator, and investigate the tripartite continuous-variable entanglement generated by this device for the first time, to our knowledge. The quantum correlation among fundamental frequency pump beam and two harmonic beams is studied using a necessary and sufficient criterion for Gaussian entanglement states, the positivity under partial transposition. It is found that two-color tripartite entanglement exists in a large range of pump intensities and analysis frequencies.
© 2010 Optical Society of America
Original Manuscript: May 12, 2010
Revised Manuscript: October 12, 2010
Manuscript Accepted: October 13, 2010
Published: November 18, 2010
Rongguo Yang, Shuqin Zhai, Kui Liu, Junxiang Zhang, and Jiangrui Gao, "Generation of multicolored tripartite entanglement by frequency doubling in a two-port resonator," J. Opt. Soc. Am. B 27, 2721-2726 (2010)