Second Harmonic Generation Enhancement From Plasmonic Toroidal Resonance in Core-Shell Nanodisk

Toroidal multipoles, together with electric and magnetic provide a complete description of electromagnetic responses matter. The fundamental toroidal resonance has been extensively achieved investigated in nanooptics, showing great ability to increase light absorption force. In this paper, we obtained plasmonic dipole core-shell (dielectric-core/gold-shell) nanodisk demonstrated an enhanced second harmonic generation (SHG) from resonance. It was shown that the based SHG depends on refractive index dielectric-core. For large cases, head-to-tail pairs form close loop, which is signature results enhancement SHG. addition, frequency red shifts as dielectric-core increases. We also cases filled several common materials. Moreover, both inner outer radius nanodisk. Such may serve for developments nonlinear nanooptics their applications.