Electromagnetic Energy Transport Above and Below the Diffraction Limit in Mesoscale Coupled-Cavity Photonic and Plasmonic Waveguides

We present a detailed and rigorous analysis of finite-size coupled-cavity optical waveguides (CCWs)-practical elements with tunable characteristics that enable guiding, routing, slowing and storing light. We discuss recent advances in design, fabrication, and applications of such structures and study mode coupling and guiding mechanisms in straight and curved CCW sections composed of optical cavities with sizes above, on and below optical wavelength. Possible ways to reduce or compensate radiation and absorption losses are proposed. These include optimal tuning of the waveguide bend geometry and exploring new classes of hybrid photonic-plasmonic mesoscale guiding structures. Application of plasmonic nanocavity arrays as optical-microcavity-coupled end-structures for focusing and channelling optical energy to single atoms, molecules, and nano-emitters is also discussed