Ultra‐confined Modes in Metal Nanoparticle Arrays for Subwavelength Light Guiding and Amplification

Propagating optical eigenmodes are found in densely packed monolayers of plasmonic nanoparticles on a metal mirror. FDTD numerical calculations show that these 2D waves carry strongly confined and amplified light energy directly in the layer of nanoparticles or in the gap between the nanoparticles and the mirror. The extreme amplification of light intensity and localization at the nanoscale offer a high potential of these waves for photon emission, light harvesting, and waveguiding applications.