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(69) Production(s) de FELBACQ D.


HOMOGENIZATION NEAR RESONANCES AND ARTIFICIAL MAGNETISM IN 3D DIELECTRIC METAMATERIALS
Auteur(s): Bouchitté Guy, Bourel Christophe, Felbacq D.
(Document sans référence bibliographique) 20151208
Ref HAL: hal01240316_v1
Ref Arxiv: 1512.02463
Ref. & Cit.: NASA ADS
Exporter : BibTex  endNote
Résumé: It is now well established that the homogenization of a periodic array of parallel dielectric fibers with suitably scaled high permittivity can lead to a (possibly) negative frequencydependent effective permeability. However this result based on a twodimensional approach holds merely in the case of linearly polarized magnetic fields, reducing thus its applications to infinite cylindrical obstacles. In this paper we consider a dielectric structure placed in a bounded domain of $\mathbb{R}^3$ and perform a full 3D asymptotic analysis. The main ingredient is a new averaging method for characterizing the bulk effective magnetic field in the vanishingperiod limit. We evidence a vectorial spectral problem on the periodic cell which determines microresonances and encodes the oscillating behavior of the magnetic field from which artificial magnetism arises. At a macroscopic level we deduce an effective permeability tensor that we can be make explicit as a function of the frequency. As far as signchanging permeability are sought after, we may foresee that periodic bulk dielectric inclusions could be an efficient alternative to the very popular metallic splitring structure proposed by Pendry.




Impedance operator description of a meta–surface with electric and magnetic dipoles
Auteur(s): Felbacq D.
(Document sans référence bibliographique)
Ref HAL: hal01182196_v1
Exporter : BibTex  endNote
Résumé: A metasurface made of a collection of nanoresonators characterized an electric dipole and a magnetic dipole was studied in the regime where the wavelength is large with respect to the size of the resonators. An effective description in terms of an impedance operator was derived.
Commentaires: Article invité pour Mathematical Problems in Engineering




Measuring enhanced optical correlations induced by transmission open channels in a slab geometry
Auteur(s): Verrier N., Depreater L, Felbacq D., Gross M.
(Document sans référence bibliographique) 20150731
Ref HAL: hal01181347_v2
Ref Arxiv: 1507.08399
Ref. & Cit.: NASA ADS
Exporter : BibTex  endNote
Résumé: Light can be transmitted through disordered media with high efficiency due to the existence of open channels, but quantitative agreement with theory is difficult to obtain because of the large number of channels to control. By measuring, by digital holography, the correlations of the transmitted field, we are able to determine the number of channels involved in transmission. With sample, the number of channels is divided by about 15 with respect to what is expected without sample. This figure is in good agreement with the theoretical prediction.




Ray Chaos in a Photonic Crystal
Auteur(s): Rousseau E., Felbacq D.
(Document sans référence bibliographique)
Ref HAL: hal01095319_v1
Ref Arxiv: 1412.4772
Ref. & Cit.: NASA ADS
Exporter : BibTex  endNote
Résumé: The ray dynamics in a photonic crystal was investigated. Chaos occurs for perfectly periodic crystals, the rays dynamics being very sensitive to the initial conditions. Depending on the filling factor, the ray dynamics can exhibit stable paths near (fully) chaotic motion. The degree of chaoticity is quantified through the computation of Lyapunov exponents. It results that the more diluted is the geometry, the more chaotic is the dynamic. Therefore, despite the perfect periodicity of the geometry, light transport is a diffusive process which can be tuned from normal diffusion (brownian motion) to anomalous diffusion because of the existence of Lévy flights.




Weak and strong coupling of a quantum emitter with a meta–surface
Auteur(s): Felbacq D.
(Document sans référence bibliographique)
Ref HAL: hal01086129_v1
Ref Arxiv: 1411.6373
Ref. & Cit.: NASA ADS
Exporter : BibTex  endNote
Résumé: Meta–surfaces are the bidimensional analogue of metamaterials. They are made on resonant elements periodically disposed on a surface. They have the ability of controlling the polarization of light and to generalized refraction laws as well. They have also been used to enhance the generation of the second harmonic. It seems however that their nearfield properties have not been investigated. In this work, the coupling of an emitter with a meta– surface made of a periodic set of resonant linear dipoles was studied. Bloch surface modes localized on the meta–surface exist due the resonance of the dipoles. The strong coupling regime with a emitter can be reached when the Bohr frequency of the emitter is in resonance with the Bloch modes of the metasurface.




Chaos and Diffusion in periodic structures
Auteur(s): Rousseau E., Felbacq D., Cassabois G.
Conférence invité: International Workshop on the Physics of Excitons (Varadero, CU, 20130330)
Ref HAL: hal01241963_v1
Exporter : BibTex  endNote
Résumé: For some conditions, we show that light propagation in perfectly periodic structures can be chaotic. Then we show that light motion is then better described by a diffusion process. We also show that the meansquare distance increase faster than linearly with time characterizing a superdiffusion process.



Spatial dispersion effects in the lowfrequency behavior of metamaterials
Auteur(s): Felbacq D.
Conférence invité: Days on Diffraction (SaintPetersbourg, RU, 20130526)
Ref HAL: hal00807704_v1
Exporter : BibTex  endNote
Résumé: The collective behavior of resonant scatterers is investigated in the low frequency regime. Evidences of a strong spatial dispersion are given.
