Numerical Analysis of Plasmonic Couplers based on Metallic Lens

Surface Plasmon Polaritons (SPPs) are evanescent surface electromagnetic waves that propagate along a dielectric-metal interface. They allow propagating modes in waveguides with dimensions smaller than the diffraction limit. By arranging slits of different widths along a metallic film, it is possible to design plasmonic lenses through phase modulation at the slits output. The distance of energy concentration, obtained by these lenses, its called focus and is of the order of one wavelength (λ). Lenses of this type allow light coming from a micrometric waveguide, such as optical fibers, for example, to be coupled to structures such as nanometric waveguides, at short distances, reducing considerably the coupling area. In this work, by using the Finite Element Method (FEM) was simulated the energy coupling between a light source and a plasmonic waveguide using plasmonic lens operating at wavelengths of 650 nm.