Enhancement of electromagnetic fields under surfaceplasmons with modified Otto and Kretschmanngeometries with graphene-dielectric structure.

In this research, we conduct a quantitative evaluation of the field intensity associated with surface plasmons (SP). This evaluation is carried out by comparing the analytical case of a plane wave applied to the Kretschmann and Otto configurations with the case of a spatially finite source. In the latter, the finite-difference time-domain (FDTD) method is employed within the aforementioned geometries. Additionally, a simulated dielectric-graphene structure is introduced in the Kretschmann configuration with the aim of enhancing the amplification and reflection properties of the magnetic field. Furthermore, the metal layer width is reduced in both configurations to determine the optimal excitation and concentration of energy at the surface. The results show that, in all cases, there exists an optimal metal or dielectric-graphene width that yields the maximum magnetic field amplitude.