Día: 16/01/2025
Hora: 
Lugar: Aula 1.A1

"Resonant cooperative scattering of light in random particulate media: homogenization and design of functional properties."
Cédric Blanchard, CNRS, CEMHTI UPR3079, Univ. Orléans, France

The effective refractive index of disordered composite is usually predicted by making use of existing effective-medium theories. Maxwell-Garnett and Bruggeman’s models are those that have had the widest use. However, even though other more elaborated models are often more accurate (e.g., Lichteneker, Felderhof, etc.), no effective-medium theory can fully described all configurations, with versatility and generality.

In this talk, the focus will be on the numerical calculation of an effective refractive index for systems of randomly distributed particles that interact resonantly. Several features will be presented.

- Practical calculation of a representative mean field.
- Concept of restricted homogenization stating that the effective index of an inhomogeneous medium has not necessarily the same range of validity as that of a homogeneous medium.
- Bergman’s representation of the effective index via a spectral density function, which carries structural information about the composite. - Eigenmodes analysis of particulate agglomerates with different shapes.
- Disordered photonics : design of controlled optical properties.