Strong Coupling in Photonics

This chapter presents a study of strong coupling between optical excitations and electronic transitions sustained in excitonic materials, emerging in core—shell nanoparticles. Here we generalize Mie theory for isotropic core—shell structures and use it to analyze the coupling strength between metallic or dielectric nanocavities encapsulated in excitonic media. In the case of plasmon—exciton coupling, we examine the emerging modes as predicted by various nonclassical models within the field of mesoscopic plasmonics, and comment on the impact of nonclassical effects on the coupling strength. We, then, consider chiral nanocavities and investigate the optical properties of the resulting chiral polaritons.