Plasmonic Dressed States

Abstract

This chapter focuses on a theoretical idea to design metallic nanostructures, that support surface plasmon, based on an analogy with the quantum principle of multiple hybridization that leads to atomic dressed states. Surface plasmon hybridization opens up new perspectives in the light manipulation at the nanoscale and related applications in nanophotonics. Several strategies have been pursued to design metallic nanostructures for specific applications such as wave-guiding, spasers, optoelectronics, multiplexing for communications. Here, we study by simulations the strong coupling regime between several surface plasmon polaritons. Multiple-hybridization between metallic layers inside plasmonic nanocavities displays properties similar to atomic dressed states. We propose to numerically and analytically investigate the case of a multilayer structure composed of stacked metallic (M) and insulator (I) thin films. For a small number of MIM blocks, the system shows discrete hybridization schemes arising from plasmonic strong coupling. When the number of layer increases, multiple and stronger couplings occur and give birth to new modes which merge to form a plasmonic energy continuum. A schematic diagram of modes construction is presented to help the design of vertical nanocavities with specific properties such as plasmonic guiding.