Concentrating the electromagnetic power in a grounded dielectric slab excited by an external Gaussian beam

A grounded dielectric film-slab is externally excited by a normally-incident Gaussian beam. A single superstrate dielectric layer, with suitably selected parameters, is placed on top of the film-slab in order to increase the power concentration inside the slab. A basic quantity of interest, called “enhancement factor” is defined, which expresses how high is the power concentration in the slab when the superstrate is present, compared to when it is absent. We demonstrate that high enhancement factor values may be achieved by choosing appropriately the physical and geometrical superstrate´s parameters.