Résumé:

We propose a space dependent homogenization scheme for a 2D media made of resonant scatterers.

Résumé:

The propagation of electromagnetic waves in a medium made of parallel dielectric rods is studied in the vicinity of the Mie resonances of the rods. It is shown that in the low frequency domain the Maxwell equations can be homogenized, which leads to an equivalent permittivity and more surprisingly to an effective permeability. It is demonstrated that the magnetic resonance is a switch for the existence of a high density of states. The effect of spatial dispersion and the properties of universality and scaling are also investigated

Ref HAL: hal-01241962_v1
DOI: 10.1103/PhysRevA.87.012101
WoS: 000312994700004
Exporter : BibTex | endNote
32 Citations
Résumé:

We discuss how the thermalization of an elementary quantum system is modified when the system is placed in an environment out of thermal equilibrium. To this aim we provide a detailed investigation of the dynamics of an atomic system placed close to a body of arbitrary geometry and dielectric permittivity, whose temperature T_M is different from that of the surrounding walls T_W. A suitable master equation for the general case of an N-level atom is first derived and then specialized to the cases of a two- and three-level atom. Transition rates and steady states are explicitly expressed as a function of the scattering matrices of the body and become both qualitatively and quantitatively different from the case of radiation at thermal equilibrium. Out of equilibrium, the system steady state depends on the system-body distance, on the geometry of the body, and on the interplay of all such parameters with the body optical resonances. While a two-level atom tends toward a thermal state, this is not the case already in the presence of three atomic levels. This peculiar behavior can be exploited, for example, to invert the populations ordering and to provide an efficient cooling mechanism for the internal state of the quantum system.We finally provide numerical studies and asymptotic expressions when the body is a slab of finite thickness. Our predictions can be relevant for a wide class of experimental configurations out of thermal equilibrium involving different physical realizations of two- or three-level systems.

Ref HAL: hal-00813434_v1
Exporter : BibTex | endNote
Résumé:

Light transport in two-dimensional disordered metamaterials made of high-permittivity rods is studied theoretically. Different regimes of transport are observed and explained in terms of coupled electric and magnetic dipolar resonances. A very general homogenization theory is derived. Light propagation at frequencies close to the magnetic dipole resonance is investigated at the microscopic level and is shown to rely on hybrid, necklace-like, states. The stability of these results versus the permittivity and disorder are investigated.

Ref HAL: hal-00808387_v1
DOI: 10.1117/12.929956
WoS: 000312960700005
Exporter : BibTex | endNote
Résumé:

A layered structured made of a dielectric waveguide and a layer of metal was studied from the point of view of the guided modes. A detailed asymptotic study of the dispersion curve was given. © (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Commentaires: http://spie.org/app/program/index.cfm?fuseaction=conferencedetail&conference_id=983825&event_id=896191

Ref HAL: hal-00808385_v1
Ref Arxiv: 1111.5631
DOI: 10.1016/j.optcom.2012.01.039
WoS: 000305854200004
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
6 Citations
Résumé:

The effect of confinement on surface plasmon polariton in a planar nanocavity was studied. The generalized modes were obtained and studied in detail. It was demonstrated that these modes result from the strong coupling of plasmon-like and photon-like modes.

Ref HAL: hal-00808377_v1
DOI: 10.1117/1.JNP.6.061504
WoS: 000304037800001
Exporter : BibTex | endNote
1 Citation
Résumé:

The homogenization of arrays of metallic rods was studied. Using standard homogenization theory, the effective permittivity was obtained. The onset of resonances was evidenced and showned to be linked with the negative sign of the real part of the permittivity. Numerical computations were performed to test the homogeneous model.