Plasmonic anapole states of active metamolecules

• DOI: 10.1364/prj.416256
• Publication Date: 2021-03-08T21:30:10Z
• Authors: Gui-Ming Pan; Fang-Zhou Shu; Le Wang; Liping Shi; Andrey B. Evlyukhin
• Keywords: Nanophotonics; Fano resonance

Anapole states, accompanied by strong suppression of light scattering, have attracted extensive attention in recent years due to their supreme performance enhancing both linear and nonlinear optical effects. Although low- high-order anapole states are observed the dielectric particles with high refractive index, so far few studies touched on topic plasmonic states. Here we demonstrate theoretically numerically that ideal (strong electric dipole scattering) can be achieved metallic metamolecules via increasing coupling strength between Cartesian toroidal moments system. The is based compensation ohmic losses a plasmon system introducing gain material, influence which well described extended coupled oscillator model. Due radiation losses, excitation systems result enhancement near fields subwavelength spatial regions outside nanoparticles. That especially important for developments nanophotonic devices active functional metamaterials, provide facilities energy concentration at nanoscale. Development considered effect increase metamolecule components discussed.