Plasmonic graded-chains as deep-subwavelength light concentrators.

摘要: We have studied the plasmonic properties of aperiodic arrays identical nanoparticles (NPs) formed by two opposite and equal graded-chains (a chain where interactions change gradually). found that these concentrate external electromagnetic fields even in long wavelength limit. The phenomenon was understood identifying system with an effective cavity plasmonics excitations are trapped between band edges, resulting from passband NP's position. Dependence excitation concentration on several parameters also assessed. This includes different gradings as well NP couplings, damping, resonant frequencies. In spirit scaling laws condensed matter physics, we developed a theory allows us to rationalize all into universal curves. is quite general can be used many other situations (different for example). Additionally, provided analytical solution, tight-binding limit, response homogeneous linear chains NPs illuminated plane wave. Our results find applications sensing, near field imaging, plasmon-enhanced photodetectors, increase solar cell efficiency.