Since the pioneering work of Maxwell Garnett [1] and Mie [2] at the turn of the century, there has been large scientific interest in the optical properties of metallic clusters [3]. Their optical behavior are driven to a large extent by the Mie excitations [3] which can be viewed as surface plasmon-polaritons [4]. Nearly hundred years ago Mie [3] derived an exact theory for the scattering of light from a free standing spherical particle. If, for isolated clusters with simple shapes, such as spheres or spheroids in vacuum, the exact solution of the Maxwell equations is well known, the difficulty of a reliable description of the optical properties of particles dramatically increases for interacting particles of complex shapes, either in a matrix or on a surface. Even though the Maxwell Garnett effective medium theory and other such theories [5] have been quite successful in tackling these questions, an accurate description of the macroscopic optical properties of a collection of particles supported on a substrate, such as the Fresnel coefficients (absorption, reflection and transmission), requires a more sophisticated approach that accounts correctly for the break of symmetry brought by the substrate and for realistic cluster shape. Indeed for clusters deposited on a surface, a quantitative description of the optical properties of thin films is not only hampered by the interactions between aggregates but also by the image interactions between the latter and the substrate [6-9].
In order to handle this latter situation in an adequate way, Bedeaux and Vlieger [10-14] in the first half of the 1970's introduced a model valid for layers whose thickness are in the sub-wavelength regime. In this case, they introduced modified boundary conditions on the surface for the electromagnetic fields which depend on what they called integrated excess quantities. In the closure relation between these quantities, they introduced surface susceptibilities which govern completely the far field behavior of the electromagnetic fields and thus the Fresnel quantities. In this way, they get rid of the complex behavior of the field on the surface. This approach is really analogous to the model of Feibelmann [15] and Barrera [16] who applied these notions in the case of the electromagnetic jump at metallic surfaces. However, Bedeaux and Vlieger were mainly interested in the description of the optical properties of island layers. For such layer, the main quantity which is directly related to the surface susceptibilities is the island polarizability. For simple shape like truncated spheres or spheroids with an axis of revolution normal to the surface of the substrate, a model based on a multipole expansion of the electrical potential in the non retarded limit was developed [17-20]. A nice recent, detailed and pedagogical introduction to this fascinating field of optics can be found in the recent book: Optical properties of Surfaces (Imperial College Press, 2001) by D. Bedeaux and J. Vlieger [21]. The aim of the present web page is to give access to the softwares which englobes most of the models developped in [21]. This software package we have named -- GranFilm.
Fuente: http://web.phys.ntnu.no/~ingves/Software/GranFilm/Current/ we have named -- GranFilm.
Nombre: Juan J. Núñez C.
Materia: CRF
Sección: 01
Leer:[Jn6:35]
In order to handle this latter situation in an adequate way, Bedeaux and Vlieger [10-14] in the first half of the 1970's introduced a model valid for layers whose thickness are in the sub-wavelength regime. In this case, they introduced modified boundary conditions on the surface for the electromagnetic fields which depend on what they called integrated excess quantities. In the closure relation between these quantities, they introduced surface susceptibilities which govern completely the far field behavior of the electromagnetic fields and thus the Fresnel quantities. In this way, they get rid of the complex behavior of the field on the surface. This approach is really analogous to the model of Feibelmann [15] and Barrera [16] who applied these notions in the case of the electromagnetic jump at metallic surfaces. However, Bedeaux and Vlieger were mainly interested in the description of the optical properties of island layers. For such layer, the main quantity which is directly related to the surface susceptibilities is the island polarizability. For simple shape like truncated spheres or spheroids with an axis of revolution normal to the surface of the substrate, a model based on a multipole expansion of the electrical potential in the non retarded limit was developed [17-20]. A nice recent, detailed and pedagogical introduction to this fascinating field of optics can be found in the recent book: Optical properties of Surfaces (Imperial College Press, 2001) by D. Bedeaux and J. Vlieger [21]. The aim of the present web page is to give access to the softwares which englobes most of the models developped in [21]. This software package we have named -- GranFilm.
Fuente: http://web.phys.ntnu.no/~ingves/Software/GranFilm/Current/ we have named -- GranFilm.
Nombre: Juan J. Núñez C.
Materia: CRF
Sección: 01
Leer:[Jn6:35]
No hay comentarios:
Publicar un comentario