Effects of mode coupling on the generation of quadrature Einstein-Podolsky-Rosen entanglement in a type-II optical parametric oscillator below threshold

Journal Article · Tue Feb 01 04:00:00 EST 2005 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.71.022313· OSTI ID:20650058

Laurat, J; Keller, G; Treps, N; Fabre, C ^[1]; Coudreau, T ^[1]

---

1. Laboratoire Kastler Brossel, UPMC, Case 74, 4 Place Jussieu, 75252 Paris cedex 05 (France)

We study theoretically and experimentally the quantum properties of a type-II frequency-degenerate optical parametric oscillator below threshold with a quarter-wave plate inserted inside the cavity which induces a linear coupling between the orthogonally polarized signal and idler fields. This original device provides a good insight into general properties of two-mode Gaussian states, illustrated in terms of the covariance matrix. We report on the experimental generation of a two-mode squeezed vacuum on nonorthogonal quadratures depending on the plate angle. After a simple operation, the entanglement is maximized and put into standard form, i.e., quantum correlations and anticorrelations on orthogonal quadratures. A half sum of squeezed variances as low as 0.33{+-}0.02, well below the unit limit for inseparability, is obtained and the entanglement measured by the entropy of formation.

• OSTI ID: 20650058
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 2 Vol. 71; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
CORRELATIONS
COUPLING
ELECTRON SPIN RESONANCE
ENERGY LEVELS
ENTROPY
INFORMATION THEORY
OPTICS
PARAMETRIC AMPLIFIERS
PARAMETRIC OSCILLATORS
PLATES
QUADRATURES
QUANTUM MECHANICS
QUANTUM NUMBERS