Broadband unidirectional scattering in visible ranges and controllable hot-spot spatial transfer via a single nanoparticle

Abstract The manipulation of optical fields plays an essential role in various areas including physics, chemistry, surface science, materials science, and nanophotonics. Herein, for the first time, we have demonstrated that a single core–shell nanoparticle features the broadband zero-backward scattering, which spans as broadly as 140 nm in the visible range. This result is acquired by tuning both the electric-dipole mode of the core and the magnetic-dipole mode of the shell, such that an effective modes coupling is achieved. By choosing special modes (or via the specific excitation laser lines), “hot spots” can be controllably transferred among the Au core surface, the shell surface, or both. This work may provide guidance for designing structures with broadband directional scattering characteristics and controllable spatial transfer of “hot spots”.