HYBRIDIZATION IN PLASMONIC NANO STRUCTURES

In this work we present an active plasmonic sub-micron device (fig. 1), which consists of a pentameric structure. The pentameric components are five identical triangular nano-cavities that are milled in a 200 nm silver opaque film. We use the hybridization between these metallic nano cavities to form new modes of plasmonic coupling, which is induced by a combination of localized and propagating surface plasmons (LSP and SPP). By tuning the polarization or the distance between these triangles, we are able to achieve suppression or enhancement of the field at specific frequencies. Herein, by minimizing the lateral device size to 200 nm (the triangular side-arm length), and less than 2 microns in length, we push the possible resolution to further increase. In addition, besides of transmission collection, we have closely inspected the fundamental behavior of the coupled entities by cathodo-luminescence (CL) measurements combined of spectra extraction and regional mapping.

Figure 1. “Rainbow of plasmonics”, the image depicts the simplicity of possible modes which can be obtained by easily changing either the polarization, or the distance between the coupled nano-triangular cavities (transmission image).