The recent interest in the imaging possibilities of photonic crystals (superlensing, superprism, ... more The recent interest in the imaging possibilities of photonic crystals (superlensing, superprism, optical mirages, etc.) call for a detailed analysis of beam propagation inside a finite periodic structure. An answer to the following question was sought: "Where does the beam emerge?" We found that, contrary to common knowledge, it is not always true that the shift of a beam is given by the normal to the dispersion curve. This phenomenon can be explained in terms of evanescent waves and a renormalized diagram yields the correct direction.
... a)Electronic mail: cabuz@ges.univ-montp2.fr ... Bloch mode at P. They follow the group veloci... more ... a)Electronic mail: cabuz@ges.univ-montp2.fr ... Bloch mode at P. They follow the group velocities, which are defined as the gradients of the respective dispersion surfaces and ... One needs to look in more detail at the spatial field distribution of the relevant Bloch modes (in our case ...
Page 1. Spatial dispersion in negative-index composite metamaterials AI Căbuz,* D. Felbacq ... »p... more Page 1. Spatial dispersion in negative-index composite metamaterials AI Căbuz,* D. Felbacq ... »period and heterogeneous period regimes, a region characterized by the phenomenon of spatial dispersion. However, since many interesting ...
Page 1. UNIVERSITE MONTPELLIER II SCIENCES ET TECHNIQUES DU LANGUEDOC THESE pour obtenir le grade... more Page 1. UNIVERSITE MONTPELLIER II SCIENCES ET TECHNIQUES DU LANGUEDOC THESE pour obtenir le grade de DOCTEUR DE L'UNIVERSITE MONTPELLIER II Discipline : Physique de la Matière Condensée Ecole Doctorale: Physique et Chimie ...
Page 1. Negative index composite metamaterials as one dimensional single negative stacks AI C˘abu... more Page 1. Negative index composite metamaterials as one dimensional single negative stacks AI C˘abuz, D. Felbacq and D. Cassagne Groupe d'Etude des Semiconducteurs UMR CNRS-UM2 5650, CC074, Université Montpellier II, Pl. ...
ABSTRACT The homogeneous and transport properties of a set of metallic fibers were studied. The e... more ABSTRACT The homogeneous and transport properties of a set of metallic fibers were studied. The existence of a plasma frequency was deduced and a precise formula for it was derived. A homogenized system for finite length ohmic wires was derived. Some numerical simulations were made to study the influence of disorder. The persistence of a low-frequency band gap was demonstrated numerically even in the case of a strong disorder. The existence of localized modes was explained in terms of the statistical properties of the medium.
We present a two-step homogenization method for composite metamaterials. First, each layer of wir... more We present a two-step homogenization method for composite metamaterials. First, each layer of wires or resonators is homogenized as a slab with negative permittivity or permeability, respectively. Second, the single negative stack which results is homogenized to form the effective medium. Comparing the predictions of the first and second step can serve as a gauge of the homogeneity of the composite. We thus take a gradual approach to homogenization, asking not whether, but to what extent a composite metamaterial approaches the sought after effective medium. Our two-step approach can also capture phenomena which otherwise may be wrongly attributed to effective medium behavior. We illustrate by qualitatively reproducing and reinterpreting a set of experimental data from the literature.
The recent interest in the imaging possibilities of photonic crystals (superlensing, superprism, ... more The recent interest in the imaging possibilities of photonic crystals (superlensing, superprism, optical mirages, etc.) call for a detailed analysis of beam propagation inside a finite periodic structure. An answer to the following question was sought: "Where does the beam emerge?" We found that, contrary to common knowledge, it is not always true that the shift of a beam is given by the normal to the dispersion curve. This phenomenon can be explained in terms of evanescent waves and a renormalized diagram yields the correct direction.
... a)Electronic mail: cabuz@ges.univ-montp2.fr ... Bloch mode at P. They follow the group veloci... more ... a)Electronic mail: cabuz@ges.univ-montp2.fr ... Bloch mode at P. They follow the group velocities, which are defined as the gradients of the respective dispersion surfaces and ... One needs to look in more detail at the spatial field distribution of the relevant Bloch modes (in our case ...
Page 1. Spatial dispersion in negative-index composite metamaterials AI Căbuz,* D. Felbacq ... »p... more Page 1. Spatial dispersion in negative-index composite metamaterials AI Căbuz,* D. Felbacq ... »period and heterogeneous period regimes, a region characterized by the phenomenon of spatial dispersion. However, since many interesting ...
Page 1. UNIVERSITE MONTPELLIER II SCIENCES ET TECHNIQUES DU LANGUEDOC THESE pour obtenir le grade... more Page 1. UNIVERSITE MONTPELLIER II SCIENCES ET TECHNIQUES DU LANGUEDOC THESE pour obtenir le grade de DOCTEUR DE L'UNIVERSITE MONTPELLIER II Discipline : Physique de la Matière Condensée Ecole Doctorale: Physique et Chimie ...
Page 1. Negative index composite metamaterials as one dimensional single negative stacks AI C˘abu... more Page 1. Negative index composite metamaterials as one dimensional single negative stacks AI C˘abuz, D. Felbacq and D. Cassagne Groupe d'Etude des Semiconducteurs UMR CNRS-UM2 5650, CC074, Université Montpellier II, Pl. ...
ABSTRACT The homogeneous and transport properties of a set of metallic fibers were studied. The e... more ABSTRACT The homogeneous and transport properties of a set of metallic fibers were studied. The existence of a plasma frequency was deduced and a precise formula for it was derived. A homogenized system for finite length ohmic wires was derived. Some numerical simulations were made to study the influence of disorder. The persistence of a low-frequency band gap was demonstrated numerically even in the case of a strong disorder. The existence of localized modes was explained in terms of the statistical properties of the medium.
We present a two-step homogenization method for composite metamaterials. First, each layer of wir... more We present a two-step homogenization method for composite metamaterials. First, each layer of wires or resonators is homogenized as a slab with negative permittivity or permeability, respectively. Second, the single negative stack which results is homogenized to form the effective medium. Comparing the predictions of the first and second step can serve as a gauge of the homogeneity of the composite. We thus take a gradual approach to homogenization, asking not whether, but to what extent a composite metamaterial approaches the sought after effective medium. Our two-step approach can also capture phenomena which otherwise may be wrongly attributed to effective medium behavior. We illustrate by qualitatively reproducing and reinterpreting a set of experimental data from the literature.
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