Optical response of composite materials: comparison of different approaches

GUILLERMO ORTIZ; MARINA INCHAUSSANDAGUE; DIANA SKIGIN; RICARDO DEPINE; LUIS MOCHÁN

Congreso; Advanced Electromagnetic Symposium 2012; 2012

We consider a composite material comprising periodically distributed metallic spheres in a dielectric host matrix. We investigate the capabilities of the effective non-retarded method (ENR) to reproduce the reflectance/transmittance of an inhomogeneous slab made of such a material. First, the effective dielectric function of the composite medium is obtained using the ENR approach, and it is introduced into the Fresnel coefficients to calculate the reflectance/ transmittance of the slab. This response is compared with that obtained with the Korringa Kohn-Rostoker (KKR) wave calculation method for various thicknesses and for different filling fractions. Within this framework, we calculate the electromagnetic response of a slab of a given thickness for different values of the lattice constant. As this value decreases, the KKR results approach those given by effective medium theories, as is to expect becausein this case the long wavelength condition is better fulfilled.