High quality asynchronous heralded single photon source at telecom wavelength

We report on the experimental realization and characterization of an asynchronous heralded single photon source based on spontaneous parametric down conversion. Photons at 1550nm are heralded as being inside a single-mode fiber with more than 60% probability, and the multi-photon emission probability is reduced by up to a factor 600 compared to poissonian light sources. These figures of merit, together with the choice of telecom wavelength for the heralded photons are compatible with practical applications needing very efficient and robust single photon sources.Comment: 7 pages, 8 figure

Niobate de lithium périodiquement polarisé à courte période et perspectives d'application

International audienceLe niobate de lithium périodiquement polarisé (PPLN) sur des périodes courantes de 6 à 22 µm trouve actuellement de nombreuses applications en optique non linéaire (ONL). La micro-structuration à plus courte période, c'est-à-dire de 2,5 µm à 300 nm, permettrait de nouvelles fonctionnalités, non seulement en ONL mais aussi en électro-optique. Les problèmes technologiques posés par ce défi sont présentés, ainsi que quelques exemples d'applications

Towards Nonlinear Photonic Wires in Z-cut LiNbO3

International audienceUsing a modified Proton Exchange process we have realized Photonic Wires in X-cut LiNbO3. They exhibit highly confined mode, low propagation losses, low strain induced polarization coupling and no reduction of the nonlinear properties. We are now transferring this technique to Z-cut LiNbO3 in order to realize very efficient nonlinear devices in PPLN

Modes Hybrides dans les Fils Quantiques Réalisés sur Niobate de Lithium en Coupe X

Dans ce papier, nous nous concentrerons sur l'influence des contraintes induites dans le cristal par le processus de fabrication des fils quantiques. Ces tensions sont responsables d'un couplage fort entre les polarisations qui confère une nature hybride aux modes se propageant et qui doit être prise en considération dans la conception des dispositifs

High-visibilty two-photon interference at a telecom wavelength using picosecond regime separated sources

We report on a two-photon interference experiment in a quantum relay configuration using two picosecond regime PPLN waveguide based sources emitting paired photons at 1550 nm. The results show that the picosecond regime associated with a guided-wave scheme should have important repercussions for quantum relay implementations in real conditions, essential for improving both the working distance and the efficiency of quantum cryptography and networking systems. In contrast to already reported regimes, namely femtosecond and CW, it allows achieving a 99% net visibility two-photon interference while maintaining a high effective photon pair rate using only standard telecom components and detectors.Comment: to appear in PRA as a rapid communicatio

Controlled Stark shifts in Er3+^{3+}-doped crystalline and amorphous waveguides for quantum state storage

We present measurements of the linear Stark effect on the $^{4}$I$_{15/2} \to$ $^{4}$I$_{13/2}$ transition in an Er$^{3+}$-doped proton-exchanged LiNbO$_{3}$ crystalline waveguide and an Er$^{3+}$-doped silicate fiber. The measurements were made using spectral hole burning techniques at temperatures below 4 K. We measured an effective Stark coefficient $(\Delta\mu_{e}\chi)/(h)=25\pm1$kHz/Vcm$^{-1}$ in the crystalline waveguide and $(\bar{\Delta\mu_{e}}\chi)/(h)=15\pm1$kHz/Vcm$^{-1}$ in the silicate fiber. These results confirm the potential of Erbium doped waveguides for quantum state storage based on controlled reversible inhomogeneous broadening.Comment: 4 pages, 2 figures v2. typo in formula correcte

The Three Hundred project: a large catalogue of theoretically modelled galaxy clusters for cosmological and astrophysical applications

We introduce the The Three Hundred project, an endeavour to model 324 large galaxy clusters with full-physics hydrodynamical re-simulations. Here we present the dataset and study the differences to observations for fundamental galaxy cluster properties and scaling relations. We find that the modelled galaxy clusters are generally in reasonable agreement with observations with respect to baryonic fractions and gas scaling relations at redshift z = 0. However, there are still some (model-dependent) differences, such as central galaxies being too massive, and galaxy colours (g − r) being bluer (about 0.2 dex lower at the peak position) than in observations. The agreement in gas scaling relations down to 1013 h−1M⊙ between the simulations indicates that particulars of the sub-grid modelling of the baryonic physics only has a weak influence on these relations. We also include – where appropriate – a comparison to three semi-analytical galaxy formation models as applied to the same underlying dark matter only simulation. All simulations and derived data products are publicly available

Development of a Questionnaire for the Search for Occupational Causes in Patients with Non-Hodgkin Lymphoma: The RHELYPRO Study

Non-Hodgkin lymphoma (NHL), multiple myeloma and chronic lymphocytic leukemia are possibly related to environmental and/or occupational exposure. The primary objective of this study was to develop a questionnaire for screening patients with these blood disorders who might benefit from a specialized consultation for possible recognition of the disease as an occupational disease. The study included 205 subjects (male gender, 67.3%; mean age, 60 years; NHL, 78.5%). The questionnaire performed very satisfactorily in identifying the exposures most frequently retained by experts for their potential involvement in the occurrence of NHL. Its sensitivity and specificity in relation to the final expertise were 96% and 96% for trichloroethylene, 85% and 82% for benzene, 78% and 87% for solvents other than trichloroethylene and dichloromethane, 87% and 95% for pesticides, respectively. Overall, 15% of the subjects were invited to ask National Social Insurance for compensation as occupational disease. These declarations concerned exposure to pesticides (64%), solvents (trichloroethylene: 29%; benzene: 18%; other than chlorinated solvents: 18%) and sometimes multiple exposures. In conclusion, this questionnaire appears as a useful tool to identify NHL patients for a specialized consultation, in order to ask for compensation for occupational disease