Towards dielectric sensing via Babinet’s principle-inspired plasmonic platforms

Localized surface plasmon (LSP) resonances in plasmonic micro-/nanostructures such as metallic spheres and cylinders, exhibit sensitivity to nearby external changes, such as variations in the refractive index of a dielectric close to the structures. This useful characteristic can be exploited in multiple fields, including medicine, and chemistry. Here, we make use of Babinet’s principle of complementarity (a concept developed for low frequencies) to design plasmonic structures at optical frequencies. The structures consist of complementary metal-dielectric cylindrical dimers and apertures on a metal film. Their performance is evaluated both experimentally and numerically demonstrating their ability to be used for sensing applications.