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Vassen W.,VU University Amsterdam | Cohen-Tannoudji C.,Kastler-Brossel Laboratory | Leduc M.,Kastler-Brossel Laboratory | Boiron D.,ParisTech Optics Institute | And 6 more authors.
Reviews of Modern Physics | Year: 2012

Experimental work on cold, trapped metastable noble gases is reviewed. The aspects which distinguish work with these atoms from the large body of work on cold, trapped atoms in general is emphasized. These aspects include detection techniques and collision processes unique to metastable atoms. Several experiments exploiting these unique features in fields including atom optics and statistical physics are described. Precision measurements on these atoms including fine structure splittings, isotope shifts, and atomic lifetimes are also discussed. © 2012 American Physical Society.

Lugan P.,ParisTech Optics Institute | Lugan P.,Albert Ludwigs University of Freiburg | Sanchez-Palencia L.,ParisTech Optics Institute
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2011

We study the Anderson localization of Bogoliubov quasiparticles (elementary many-body excitations) in a weakly interacting Bose gas of chemical potential μ subjected to a disordered potential V. We introduce a general mapping (valid for weak inhomogeneous potentials in any dimension) of the Bogoliubov-de Gennes equations onto a single-particle Schrödinger-like equation with an effective potential. For disordered potentials, the Schrödinger-like equation accounts for the scattering and localization properties of the Bogoliubov quasiparticles. We derive analytically the localization lengths for correlated disordered potentials in the one-dimensional geometry. Our approach relies on a perturbative expansion in V/μ, which we develop up to third order, and we discuss the impact of the various perturbation orders. Our predictions are shown to be in very good agreement with direct numerical calculations. We identify different localization regimes: For low energy, the effective disordered potential exhibits a strong screening by the quasicondensate density background, and localization is suppressed. For high-energy excitations, the effective disordered potential reduces to the bare disordered potential, and the localization properties of quasiparticles are the same as for free particles. The maximum of localization is found at intermediate energy when the quasicondensate healing length is of the order of the disorder correlation length. Possible extensions of our work to higher dimensions are also discussed. © 2011 American Physical Society.

Kheruntsyan K.V.,University of Queensland | Jaskula J.-C.,ParisTech Optics Institute | Jaskula J.-C.,Harvard - Smithsonian Center for Astrophysics | Deuar P.,Polish Academy of Sciences | And 7 more authors.
Physical Review Letters | Year: 2012

The Cauchy-Schwarz (CS) inequality-one of the most widely used and important inequalities in mathematics-can be formulated as an upper bound to the strength of correlations between classically fluctuating quantities. Quantum-mechanical correlations can, however, exceed classical bounds. Here we realize four-wave mixing of atomic matter waves using colliding Bose-Einstein condensates, and demonstrate the violation of a multimode CS inequality for atom number correlations in opposite zones of the collision halo. The correlated atoms have large spatial separations and therefore open new opportunities for extending fundamental quantum-nonlocality tests to ensembles of massive particles. © 2012 American Physical Society.

De Oliveira N.,Synchrotron Soleil | Roudjane M.,Synchrotron Soleil | Roudjane M.,University of Kentucky | Joyeux D.,Synchrotron Soleil | And 4 more authors.
Nature Photonics | Year: 2011

Vacuum-ultraviolet (VUV) high-resolution absorption spectroscopy is a unique tool for the study of gas-phase atomic and molecular electronic structure. To date, it has been performed by using lasers or synchrotron radiation-based grating spectrometers, but none of these techniques can offer simultaneous high resolution, wavelength accuracy and broad tunability. The only technique combining these three important features is Fourier-transform spectroscopy, but this is limited to the mid-UV range (down to 140 nm; ref. 1) because of a lack of beamsplitters. Here, we present a new instrument based on a wavefront-division scanning interferometer, applied for the first time to the VUV range. This instrument, coupled to the DESIRS beamline at synchrotron SOLEIL, covers a broad range of wavelengths (typically 7%, adjustable in the 250g-40 nm range), a resolving power of ∼1 × 106, an extrinsic absolute wavelength accuracy of 1 × 10-7 and a high signal-to-noise ratio. © 2011 Macmillan Publishers Limited. All rights reserved.

Maksymov I.S.,ParisTech Optics Institute | Besbes M.,ParisTech Optics Institute | Hugonin J.P.,ParisTech Optics Institute | Yang J.,ParisTech Optics Institute | And 4 more authors.
Physical Review Letters | Year: 2010

A novel metal-coated nanocylinder-cavity architecture fully compatible with III-V GaInAs technology and benefiting from a broad spectral range enhancement of the local density of states is proposed as an integrated source of nonclassical light. Because of a judicious selection of the mode volume, the cavity combines good collection efficiency (≈45%), large Purcell factors (≈15) over a 80 nm spectral range, and a low sensitivity to inevitable spatial mismatches between the single emitter and the cavity mode. This represents a decisive step towards the implementation of reliable solid-state devices for the generation of entangled photon pairs at infrared wavelengths. © 2010 The American Physical Society.

Liu H.,Nankai University | Lalanne P.,ParisTech Optics Institute
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

We present a simple and intuitive model for analyzing the optical response of metallic surfaces patterned by arbitrary one-dimensional arrays of subwavelength (sub- λ) structures. In the present microscopic approach, the near-field response close to the surface is composed of a linear combination of elementary hybrid waves, which are shown to solely depend on the frequency and to be merely independent of the incident illumination and of the scatterer geometry. The model is tested against fully vectorial computational results obtained for simple systems that can be handled numerically with fully vectorial methods and, in contrast to classical models that solely rely on surface plasmon polaritons, the present model is shown to be highly accurate over a broad spectral range below the plasma frequency of the metal. © 2010 The American Physical Society.

Liu H.,Nankai University | Lalanne P.,ParisTech Optics Institute
Journal of the Optical Society of America A: Optics and Image Science, and Vision | Year: 2010

As shown in a recent letter [Nature 452, 728 (2008)] with a microscopic model, the phenomenon of the extraordinary optical transmission (EOT) is intrinsically due to two distinct surface waves: the surface plasmon polariton and the quasi-cylindrical wave (quasi-CW) that efficiently funnel light into the hole aperture at resonance. Here we present a comprehensive microscopic model of the EOT that takes into account the two surface waves. The model preserves the desirable physical insight of the previous approach, but since it additionally takes into account the quasi-CWs, it provides highly accurate predictions over a much broader spectral range, from visible to microwave radiation. The net outcome is a complete understanding of many aspects of the EOT and especially of the role of the metal conductivity that has largely puzzled the initial interpretations. We believe that the main conclusions of the present analysis may be applied to many Wood-type surface resonances on metallic surfaces. © 2010 Optical Society of America.

Vrijsen G.,Stanford University | Hosten O.,Stanford University | Lee J.,Stanford University | Bernon S.,Stanford University | And 2 more authors.
Physical Review Letters | Year: 2011

We demonstrate a Raman laser using cold Rb87 atoms as the gain medium in a high-finesse optical cavity. We observe robust continuous wave lasing in the atypical regime where single atoms can considerably affect the cavity field. Consequently, we discover unusual lasing threshold behavior in the system causing jumps in lasing power, and propose a model to explain the effect. We also measure the intermode laser linewidth, and observe values as low as 80Hz. The tunable gain properties of this laser suggest multiple directions for future research. © 2011 American Physical Society.

Paurisse M.,ParisTech Optics Institute | Hanna M.,ParisTech Optics Institute | Druon F.,ParisTech Optics Institute | Georges P.,ParisTech Optics Institute
Optics Letters | Year: 2010

We demonstrate the active wavefront control of a 19-core ytterbium-doped fiber amplifier by the digital holography technique. The output wavefront is corrected even in the presence of large externally induced perturbations, with a measured output Strehl ratio of 0.6 in all cases. The wavefront-controlled multicore fiber is used to amplify 800 ps pulses at 1064 nm at a repetition rate of 40 kHz, and a gain of 23 dB is obtained. © 2010 Optical Society of America.

Druon F.,ParisTech Optics Institute | Balembois F.,ParisTech Optics Institute | Georges P.,ParisTech Optics Institute
IEEE Photonics Journal | Year: 2011

Laser amplifiers seek high power, efficiency, and short pulse durations. Research laboratories in this field have focused their investigations toward new laser materials that can be efficiently diode pumped, sustain high-power pumping, and have broad emission bandwidth to achieve ultrashort pulse amplification. This is why, for more than ten years now, new Yb-doped materials have been intensively investigated. In the actual state of the art, they represent the more promising and successful materials for these kinds of applications. In this paper, we will do a short review of the last and more impacting discoveries and demonstrations in this field over the last few years. © 2011 IEEE.

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