Perfil de campo eléctrico en estructuras multicapa

Abstract

There are several natural systems that can be modeled as multi-layer systems. The skin, the earth's crust, biological systems such as the mitochondria, are just some practical examples. Perhaps, the main interest in multilayer systems is the development of new materials with physical properties on demand. In particular, in relation to optical properties, the design of suitable structures with multiple layers made of different materials has allowed the design of materials with extraordinary optical responses. On the other hand, recent advances in nanofabrication have allowed access to additional degrees of freedom in the design of such structures by exploiting new properties that arise only in this scale. Of particular interest have been the metallic nanostructures where optical excitations take place giving rise to extraordinary phenomena that involve a strong confinement of the electric field to the surface of such nanostructures with innumerable practical applications. These optical excitations are associated with collective oscillations of the free electrons of the metal called surface plasmons. Depending on the type of metallic structures supporting this type of excitations, localized surface plasmons are conceived for the case of isolated metal structures (nanoparticles), and propagating surface plasmons (SPP) for the case of ultra-thin continuous layers. These optical excitations have associated unusual absorptions that can be controlled by manipulating the structural properties. In this way multilayer structures allow to conceive a mechanism of control of these excitations and consequently of the effective optical properties of the structures that support them.