title: Experimental demonstration of quantum entanglement between frequency-nondegenerate optical twin beams.
abstract: The quantum entanglement of amplitude and phase quadratures between two intense optical beams with a total intensity of 22 mW and a frequency difference of 1 nm, which are produced from an optical parametric oscillator operating above threshold, is experimentally demonstrated with two sets of unbalanced Mach-Zehnder interferometers. The measured quantum correlations of intensity and phase are in reasonable agreement with the results calculated based on a semiclassical analysis of the noise characteristics given by Fabre et al. [J. Phys. (France) 50, 1209 (1989)].
authors.affiliation: State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University, Taiyuan 030006, China.
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Su
authors.forename: Aihong
authors.initials: A
authors.lastname: Tan
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Jia
authors.forename: Qing
authors.initials: Q
authors.lastname: Pan
authors.forename: Changde
authors.initials: C
authors.lastname: Xie
authors.forename: Kunchi
authors.initials: K
authors.lastname: Peng