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Daems D.,Laboratory Interdisciplinaire Carnot de Bourgogne | Ruschhaupt A.,University College Cork | Sugny D.,Laboratory Interdisciplinaire Carnot de Bourgogne | Guerin S.,Laboratory Interdisciplinaire Carnot de Bourgogne
Physical Review Letters | Year: 2013

Considering the problem of the control of a two-state quantum system by an external field, we establish a general and versatile method allowing the derivation of smooth pulses which feature the properties of high fidelity, robustness, and low area. Such shaped pulses can be interpreted as a single-shot generalization of the composite pulse-sequence technique with a time-dependent phase. © 2013 American Physical Society.


Fatome J.,Laboratory Interdisciplinaire Carnot de Bourgogne | Finot C.,Laboratory Interdisciplinaire Carnot de Bourgogne | Millot G.,Laboratory Interdisciplinaire Carnot de Bourgogne | Armaroli A.,Max Planck Institute for the Science of Light | Trillo S.,University of Ferrara
Physical Review X | Year: 2014

We demonstrate that wave-breaking dramatically affects the dynamics of nonlinear frequency conversion processes that operate in the regime of high efficiency (strong multiple four-wave mixing). In particular, by exploiting an all-optical-fiber platform, we show that input modulations propagating in standard telecom fibers in the regime of weak normal dispersion lead to the formation of undular bores (dispersive shock waves) that mimic the typical behavior of dispersive hydrodynamics exhibited, e.g., by gravity waves and tidal bores. Thanks to the nonpulsed nature of the beat signal employed in our experiment, we are able to clearly observe how the periodic nature of the input modulation forces adjacent undular bores to collide elastically.


Da Pieve F.,Vrije Universiteit Brussel | Kruger P.,Laboratory Interdisciplinaire Carnot de Bourgogne
Physical Review Letters | Year: 2013

A first principles approach for spin- and angle-resolved resonant photoemission is developed within multiple scattering theory and applied to a Cr(110) surface at the 2p-3d resonance. The resonant photocurrent from this nonferromagnetic system is found to be strongly spin polarized by circularly polarized light, in agreement with experiments on antiferromagnetic and magnetically disordered systems. By comparing the antiferromagnetic and Pauli-paramagnetic phases of Cr, we explicitly show that the spin polarization of the photocurrent is independent of the existence of local magnetic moments, solving a long-standing debate on the origin of such polarization. New spin polarization effects are predicted for the paramagnetic phase even with unpolarized light, opening new directions for full mapping of spin interactions in macroscopically nonmagnetic or nanostructured systems. © 2013 American Physical Society.


Finot C.,Laboratory Interdisciplinaire Carnot de Bourgogne
Optics Letters | Year: 2015

We show that the amplitude and phase shaping of only four sidebands of the optical spectrum is sufficient to synthesize parabolic, triangular, or flat-top pulse trains at high repetition rates. Selection of the symmetric carriersuppressed waveform is easily achieved by changing the phase difference between the inner and outer spectral lines. Experiments carried out at a repetition rate of 40 GHz confirm the high quality of the intensity profiles that are obtained. © 2015 Optical Society of America.


Chevalier S.,Laboratory Interdisciplinaire Carnot de Bourgogne
Materials and Corrosion | Year: 2014

Materials able to form protective chromia, Cr2O3, are most of time good candidates to be used at high temperatures in oxidizing atmospheres. Minor element additions are necessary to increase their mechanical or chemical properties. Among them, the reactive elements (RE) are highly efficient to improve the high temperature oxidation behavior of alloys.Their addition in small quantity is enough to greatly decrease the oxidation rates, but above all to drastically increase the oxide scale adherence to the basematerials.Thatwas the key point of what observed Pfeil 75 years ago. Since that date, many results have been published, many theories have been proposed, and many discussions have been engaged. Until now, the reasons why RE are so efficient are not fully understood, several hypotheses have been proposed in order to explain their beneficial effect on the oxide scale formation. According to the large amounts of published papers on this topic, there is probably no single theory envisageable to explain their role, whatever their nature, the tested materials and then the native oxide scale, as well as the nature of the oxidizing atmosphere.The decrease of the oxidation rate and the improvement of the oxide layer adherence are the final results due to RE additions. Generally, RE additions favor the nucleation and the growth of scales. They decrease the oxide grain size, and consequently could change scale plasticity and creep, which can modify the growth and/or thermal stresses generated within the scale during its growth or its cooling to room temperature. They prevent the detrimental sulfur effect and suppress dislocation climb in the metal and, then, limit cation transport (poisoned interface model). 75th Pfeil's patent anniversary seems good to make a pause in order to analyze what we really understood on the reactive element effect in chromia-forming materials. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Millot G.,Laboratory Interdisciplinaire Carnot de Bourgogne | Wabnitz S.,University of Brescia
Journal of the Optical Society of America B: Optical Physics | Year: 2014

We review polarization stabilization techniques based on the polarization attraction effect in low-birefringence fibers. Polarization attraction or pulling may be based on cross-polarization modulation, on parametric amplification, and on Raman or Brillouin scattering. We also review methods for laser frequency conversion based on polarization modulation instabilities in low-and high-birefringence fibers, and photonic crystal fibers. Polarization instabilities in nonlinear fibers may also be exploited for sensing applications. © 2014 Optical Society of America.


Nalet C.,Laboratory Interdisciplinaire Carnot de Bourgogne | Nonat A.,Laboratory Interdisciplinaire Carnot de Bourgogne
Cement and Concrete Research | Year: 2016

The ion complexing power and the adsorption of set-retarders such as sugar derivatives (D-glucitol, D-gluconate…), amino-carboxylates and phosphonates (EDTA, EDTMP, …) on C-S-H were identified and compared. The complexation equilibria of the predominant calcium and/or hydroxide complex and its relative constant were determined after measuring the solubilizing effect of the molecules in suspensions buffered by portlandite. The adsorption of the molecules on C-S-H as well as their possible complexation with silicate ions in solution were also investigated. All the molecules studied are shown to complex calcium and/or hydroxide ions but only amino-phosphonates, D-gluconate and D-glucitol complex silicate ions. They all adsorb on portlandite and C-S-H but to different extents. These organic compounds are also revealed to be sensitive to the presence of calcium counter-ions at the surface of C-S-H. Finally, the relation between their ionic complexing powers, adsorption properties and retarding effects on the hydration of C3S are discussed. © 2016 Elsevier Ltd


Guasoni M.,Laboratory Interdisciplinaire Carnot de Bourgogne
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2015

In this paper intermodal modulational instability (IM-MI) is analyzed in a multimode fiber where several spatial and polarization modes propagate. The coupled nonlinear Schrödinger equations describing the modal evolution in the fiber are linearized and reduced to an eigenvalue problem. As a result, the amplification of each mode can be described by means of the eigenvalues and eigenvectors of a matrix that stores the information about the dispersion properties of the modes and the modal power distribution of the pump. Some useful analytical formulas are also provided that estimate the modal amplification as function of the system parameters. Finally, the impact of third-order dispersion and of absorbtion losses is evaluated, which reveals some surprising phenomena into the IM-MI dynamics. These outcomes generalize previous studies on bimodal MI, related to the interaction between two spatial or polarization modes, to the most general case of N>2 interacting modes. Moreover, they pave the way towards the realization of wideband multimode parametric amplifiers. © 2015 American Physical Society.


Frisquet B.,Laboratory Interdisciplinaire Carnot de Bourgogne | Kibler B.,Laboratory Interdisciplinaire Carnot de Bourgogne | Millot G.,Laboratory Interdisciplinaire Carnot de Bourgogne
Physical Review X | Year: 2014

We report here a novel fiber-based test bed using tailored spectral shaping of an optical-frequency comb to excite the formation of two Akhmediev breathers that collide during propagation. We have found specific initial conditions by controlling the phase and velocity differences between breathers that lead, with certainty, to their efficient collision and the appearance of a giant-amplitude wave. Temporal and spectral characteristics of the collision dynamics are in agreement with the corresponding analytical solution. We anticipate that experimental evidence of breather-collision dynamics is of fundamental importance in the understanding of extreme ocean waves and in other disciplines driven by the continuous nonlinear Schrödinger equation.


Coillet A.,Laboratory Interdisciplinaire Carnot de Bourgogne | Grelu P.,Laboratory Interdisciplinaire Carnot de Bourgogne
Optics Communications | Year: 2012

Using optical microfibers, phase matching between different propagation modes allows for third-harmonic generation (THG). After detailing the relevant phase matching conditions and overlap integrals, we provide a comparison between THG effective efficiencies in silica and tellurite glasses. We also explain the relatively easy, wideband, conversion that we observe experimentally in silica glass microfibers, from 1.55 μm to the green, by the geometry of the tapering region. © 2012 Elsevier B.V. All rights reserved.

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