3 research outputs found
Generation of Bright Two-Color Continuous Variable Entanglement
We present the first measurement of squeezed-state entanglement between the
twin beams produced in an Optical Parametric Oscillator (OPO) operating above
threshold. Besides the usual squeezing in the intensity difference between the
twin beams, we have measured squeezing in the sum of phase quadratures. Our
scheme enables us to measure such phase anti-correlations between fields of
different frequencies. In the present measurements, wavelengths differ by ~1
nm. Entanglement is demonstrated according to the Duan et al. criterion [Phys.
Rev. Lett. 84, 2722 (2000)] .
This experiment opens the way for new potential applications such as the
transfer of quantum information between different parts of the electromagnetic
spectrum.Comment: 4 pages, 3 figures, submitted to Phys. Rev. Let
Characterization of bipartite states using a single homodyne detector
We suggest a scheme to reconstruct the covariance matrix of a two-mode state
using a single homodyne detector plus a polarizing beam splitter and a
polarization rotator. It can be used to fully characterize bipartite Gaussian
states and to extract relevant informations on generic states.Comment: 7 pages, 1 figur
Entanglement of two-mode Gaussian states: characterization and experimental production and manipulation
A powerful theoretical structure has emerged in recent years on the
characterization and quantification of entanglement in continuous-variable
systems. After reviewing this framework, we will illustrate it with an original
set-up based on a type-II OPO with adjustable mode coupling. Experimental
results allow a direct verification of many theoretical predictions and provide
a sharp insight into the general properties of two-mode Gaussian states and
entanglement resource manipulation