160 research outputs found
Teleportation of an atomic ensemble quantum state
We propose a protocol to achieve high fidelity quantum state teleportation of
a macroscopic atomic ensemble using a pair of quantum-correlated atomic
ensembles. We show how to prepare this pair of ensembles using quasiperfect
quantum state transfer processes between light and atoms. Our protocol relies
on optical joint measurements of the atomic ensemble states and magnetic
feedback reconstruction
Generation of two-color polarization-entangled optical beams with a self-phase-locked two-crystal Optical Parametric Oscillator
A new device to generate polarization-entangled light in the continuous
variable regime is introduced. It consists of an Optical Parametric Oscillator
with two type-II phase-matched non-linear crystals orthogonally oriented,
associated with birefringent elements for adjustable linear coupling. We give
in this paper a theoretical study of its classical and quantum properties. It
is shown that two optical beams with adjustable frequencies and well-defined
polarization can be emitted. The Stokes parameters of the two beams are
entangled. The principal advantage of this setup is the possibility to directly
generate polarization entangled light without the need of mixing four modes on
beam splitters as required in current experimental setups. This device opens
new directions for the study of light-matter interfaces and generation of
multimode non-classical light and higher dimensional phase space
Continuous-wave phase-sensitive parametric image amplification
We study experimentally parametric amplification in the continuous regime
using a transverse-degenerate type-II Optical Parametric Oscillator operated
below threshold. We demonstrate that this device is able to amplify either in
the phase insensitive or phase sensitive way first a single mode beam, then a
multimode image. Furthermore the total intensities of the amplified image
projected on the signal and idler polarizations are shown to be correlated at
the quantum level.Comment: 14 pages, 7 figures, submitted to Journal of Modern Optics, Special
Issue on Quantum Imagin
Recovery of continuous wave squeezing at low frequencies
We propose and demonstrate a system that produces squeezed vacuum using a
pair of optical parametric amplifiers. This scheme allows the production of
phase sidebands on the squeezed vacuum which facilitate phase locking in
downstream applications. We observe strong, stably locked, continuous wave
vacuum squeezing at frequencies as low as 220 kHz. We propose an alternative
resonator configuration to overcome low frequency squeezing degradation caused
by the optical parametric amplifiers.Comment: 9 pages, 4 figure
- …