98 research outputs found
Purcell factor for point-like dipolar emitter coupling to 2D-plasmonic waveguides
We theoretically investigate the spontaneous emission of a point--like
dipolar emitter located near a two--dimensional (2D) plasmonic waveguide of
arbitrary form. We invoke an explicite link with the density of modes of the
waveguide describing the electromagnetic channels into which the emitter can
couple. We obtain a closed form expression for the coupling to propagative
plasmon, extending thus the Purcell factor to plasmonic configurations.
Radiative and non-radiative contributions to the spontaneous emission are also
discussed in details
Near-field properties of plasmonic nanostructures with high aspect ratio
Using the Green's dyad technique based on cuboidal meshing, we compute the
electromagnetic field scattered by metal nanorods with high aspect ratio. We
investigate the effect of the meshing shape on the numerical simulations. We
observe that discretizing the object with cells with aspect ratios similar to
the object's aspect ratio improves the computations, without degrading the
convergency. We also compare our numerical simulations to finite element method
and discuss further possible improvements
Mode-selective quantization and multimodal effective models for spherically layered systems
We propose a geometry-specific, mode-selective quantization scheme in coupled
field-emitter systems which makes it easy to include material and geometrical
properties, intrinsic losses as well as the positions of an arbitrary number of
quantum emitters. The method is presented through the example of a spherically
symmetric, non-magnetic, arbitrarily layered system. We follow it up by a
framework to project the system on simpler, effective cavity QED models.
Maintaining a well-defined connection to the original quantization, we derive
the emerging effective quantities from the full, mode-selective model in a
mathematically consistent way. We discuss the uses and limitations of these
effective models
Polarization state of the optical near-field
The polarization state of the optical electromagnetic field lying several
nanometers above complex dielectric structures reveals the intricate
light-matter interaction that occurs in this near-field zone. This information
can only be extracted from an analysis of the polarization state of the
detected light in the near-field. These polarization states can be calculated
by different numerical methods well-suited to near--field optics. In this
paper, we apply two different techniques (Localized Green Function Method and
Differential Theory of Gratings) to separate each polarisation component
associated with both electric and magnetic optical near-fields produced by
nanometer sized objects. The analysis is carried out in two stages: in the
first stage, we use a simple dipolar model to achieve insight into the physical
origin of the near-field polarization state. In the second stage, we calculate
accurate numerical field maps, simulating experimental near-field light
detection, to supplement the data produced by analytical models. We conclude
this study by demonstrating the role played by the near-field polarization in
the formation of the local density of states.Comment: 9 pages, 11 figures, accepted for publication in Phys. Rev.
Fano resonances in plasmonic core-shell particles and the Purcell effect
Despite a long history, light scattering by particles with size comparable
with the light wavelength still unveils surprising optical phenomena, and many
of them are related to the Fano effect. Originally described in the context of
atomic physics, the Fano resonance in light scattering arises from the
interference between a narrow subradiant mode and a spectrally broad radiation
line. Here, we present an overview of Fano resonances in coated spherical
scatterers within the framework of the Lorenz-Mie theory. We briefly introduce
the concept of conventional and unconventional Fano resonances in light
scattering. These resonances are associated with the interference between
electromagnetic modes excited in the particle with different or the same
multipole moment, respectively. In addition, we investigate the modification of
the spontaneous-emission rate of an optical emitter at the presence of a
plasmonic nanoshell. This modification of decay rate due to electromagnetic
environment is referred to as the Purcell effect. We analytically show that the
Purcell factor related to a dipole emitter oriented orthogonal or tangential to
the spherical surface can exhibit Fano or Lorentzian line shapes in the near
field, respectively.Comment: 28 pages, 10 figures; invited book chapter to appear in "Fano
Resonances in Optics and Microwaves: Physics and Application", Springer
Series in Optical Sciences (2018), edited by E. O. Kamenetskii, A. Sadreev,
and A. Miroshnichenk
Localisation de gènes de structure et de régulateurs chez le blé tendre, Triticum aestivum L. par electrophorèse bidimensionnelle des protéines
*INRA, Unité de Génétique et d'Amélioration des Plantes, route de Saint Cyr, 78026 Versailles Cedex Diffusion du document : INRA, Unité de Génétique et d'Amélioration des Plantes, route de Saint Cyr, 78026 Versailles Cedex Diplôme : Dr. d'Universit
Localisation de gènes de structure et de régulateurs chez le blé tendre, Triticum aestivum L. par electrophorèse bidimensionnelle des protéines
*INRA, Unité de Génétique et d'Amélioration des Plantes, route de Saint Cyr, 78026 Versailles Cedex Diffusion du document : INRA, Unité de Génétique et d'Amélioration des Plantes, route de Saint Cyr, 78026 Versailles Cedex Diplôme : Dr. d'Universit
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