175 research outputs found
Spectral hole burning for stopping light
We propose a novel protocol for storage and retrieval of photon wave packets
in a -type atomic medium. This protocol derives from spectral hole
burning and takes advantages of the specific properties of solid state systems
at low temperature, such as rare earth ion doped crystals. The signal pulse is
tuned to the center of the hole that has been burnt previously within the
inhomogeneously broadened absorption band. The group velocity is strongly
reduced, being proportional to the hole width. This way the optically carried
information and energy is carried over to the off-resonance optical dipoles.
Storage and retrieval are performed by conversion to and from ground state
Raman coherence by using brief -pulses. The protocol exhibits some
resemblance with the well known electromagnetically induced transparency
process. It also presents distinctive features such as the absence of coupling
beam. In this paper we detail the various steps of the protocol, summarize the
critical parameters and theoretically examine the recovery efficiency.Comment: 17 pages, 6 figures, submitted to Phys. Rev.
On the impossibility of faithfully storing single-photons with the three-pulse photon echo
The three-pulse photon echo is a well-known technique to store intense light
pulses in an inhomogeneously broadened atomic ensemble. This protocol is
attractive because it is relatively simple and it is well suited for the
storage of multiple temporal modes. Furthermore, it offers very long storage
times, greater than the phase relaxation time. Here, we consider the
three-pulse photon echo in both two- and three-level systems as a potential
technique for the storage of light at the single-photon level. By explicit
calculations, we show that the ratio between the echo signal corresponding to a
single-photon input and the noise is smaller than one. This severely limits the
achievable fidelity of the quantum state storage, making the three-pulse photon
echo unsuitable for single-photon quantum memory.Comment: 6 pages, 4 figure
Stimulated Raman adiabatic passage in Tm3+:YAG
International audienceWe report on the experimental demonstration of stimulated Raman adiabatic passage in a Tm 3+ : YAG crystal. Tm 3+ : YAG is a promising material for use in quantum information processing applications, but as yet there are few experimental investigations of coherent Raman processes in this material. We investigate the effect of inhomogeneous broadening and Rabi frequency on the transfer efficiency and the width of the two-photon spectrum. Simulations of the complete Tm 3+ : YAG system are presented along with the corresponding experimental results
Time gating of heralded single photons for atomic memories
We demonstrate a method for time gating the standard heralded continuous-
wave (cw) spontaneous parametric down-converted (SPDC) single photon source by
using pulsed pumping of the optical parametric oscillator (OPO) below
threshold. The narrow bandwidth, high purity, high spectral brightness and the
pseudo-deterministic character make the source highly suitable for light-atom
interfaces with atomic memories.Comment: Accepted for publication in Optics Letter
Low-frequency vacuum squeezing via polarization self-rotation in Rb vapor
We observed squeezed vacuum light at 795 nm in 87Rb vapor via resonant
polarization self-rotation, and report noise sidebands suppression of ~1 dB
below shot noise level spanning from acoustic (30 kHz) to MHz frequencies. This
is the first demonstration of sub-MHz quadrature vacuum squeezing in atomic
systems. The spectral range of observed squeezing matches well typical
bandwidths of electromagnetically induced transparency (EIT) resonances, making
this simple technique for generation of optical fields with non-classical
statistics at atomic transitions wavelengths attractive for EIT-based quantum
information protocols applications.Comment: 4 pages, 3 figure
Broadband stimulated four-wave parametric conversion on a tantalum pentoxide photonic chip
We exploit the large third order nonlinear susceptibility (?(3) or “Chi 3”) of tantalum pentoxide (Ta2O5) planar waveguides and realize broadband optical parametric conversion on-chip. We use a co-linear pump-probe configuration and observe stimulated four wave parametric conversion when seeding either in the visible or the infrared. Pumping at 800 nm we observe parametric conversion over a broad spectral range with the parametric idler output spanning from 1200 nm to 1600 nm in infrared wavelengths and from 555 nm to 600 nm in visible wavelengths. Our demonstration of on-chip stimulated four wave parametric conversion introduces Ta2O5 as a novel material for broadband integrated nonlinear photonic circuit applications
Coherent Control of Stationary Light Pulses
We present a detailed analysis of the recently demonstrated technique to
generate quasi-stationary pulses of light [M. Bajcsy {\it et al.}, Nature
(London) \textbf{426}, 638 (2003)] based on electromagnetically induced
transparency. We show that the use of counter-propagating control fields to
retrieve a light pulse, previously stored in a collective atomic Raman
excitation, leads to quasi-stationary light field that undergoes a slow
diffusive spread. The underlying physics of this process is identified as pulse
matching of probe and control fields. We then show that spatially modulated
control-field amplitudes allow us to coherently manipulate and compress the
spatial shape of the stationary light pulse. These techniques can provide
valuable tools for quantum nonlinear optics and quantum information processing.Comment: 27 pages, 10 figure
Improving single-photon sources with Stark tuning
We investigate the use of the Stark shift in atomlike systems in order to control the interaction with a high-Q/V microcavity. By applying a Stark shift pulse to a single atomlike system, in order to affect and control its detuning from a cavity resonance, the cavity QED interaction can be carefully controlled so as to allow stochastic pumping of the emitting state without causing random timing jitter in the output photon. Using a quantum trajectory approach, we conduct simulations that show this technique is capable of producing indistinguishable single photons that exhibit complete Hong-Ou-Mandel interference. Furthermore, Stark tuning control allows for the generation of arbitrary pulse envelopes. We demonstrate this by showing that a simple asymmetric Stark shifting pulse can lead to the emission of symmetric Gaussian single-photon pulse envelopes, rather than the usual exponential decay. These Gaussian pulses also exhibit complete Hong-Ou-Mandel interference. The use of Stark shifting in solid-state systems could ultimately provide the cheap miniature high quality single-photon sources that are currently required for applications such as all-optical quantum computing
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