Nonlinear Plasmonics in Metamaterials

The target of the work is to use Transformation Optics TO in order to guide as well as focus plasmons. In the initial phase of the work we focused on using TO to GRaded INdex GRIN Lenses of Luneburg type and explored focusing and guiding. In particular we showed both analytically and numerically with home-made codes that for plane wave initial conditions a A sequence of Luneburg lenses can form a waveguide with low losses that can guide EM waves in linear as well as curved geometries b Random distributions of Luneburg lenses can lead to the formation of caustics and optical rogue waves and c We used commercial code COMSOL and generated plasmon waves at a metal-dielectric interface. Subsequently we analyzed propagation of Gaussian beams and found that Luneburg lens focusing is not as good as in the case of plane waves. In this case, the addition of nonlinearity of the Kerr type improves focusing and thus propagation in the Luneburg waveguides. In the case of plasmon propagation we found that Luneburg lenses may focus plasmons in a resonant fashion. The results of the Luneburg work formed a manuscript that has been invited to a special volume to be published in the Journal of Optics. This article is currently under review. We anticipate the preparation of one more article with the nonlinear effects.