Controlled light scattering of a single nanoparticle by wavefront shaping

Controlling light scattering by nanoparticles is fundamentally important for the understanding and the control of light with photonic nanostructures, as well as for nanoparticle scattering itself, including Mie scattering. Here, we theoretically and numerically investigate the possibility to manipulate nanoparticle scattering by wavefront shaping that was initially developed to control light scattered by large numbers of nanoparticles in nanophotonic media. By employing a scattering matrix analysis, we find that even a single nanoparticle supports multiple strongly scattering eigenchannels, suggesting wavefront shaping as a promising tool to manipulate scattered light of a single nanoparticle. By sending in shaped wavefronts, we selectively excite eigenchannels, as is apparent from the distinct field distributions. These scattering eigenchannels are related to different resonant leaky modes of the scatterer, that reveal remarkable localized "hot spots" where the field is substantially enhanced. Moreover, we investigate the backscattered spectra; to this send in wavefronts relevant for a particular eigenchannel, and observe that the backscattered spectrum reveals not only the excited channel but also several others. This result points to the existence of short and long-range spectral correlations for an eigenchannel. Our work offers a flexible tool to manipulate light scattering of a single nanoparticle, and thus opens new possibilities to control field patterns and light-matter interactions in a nanoparticle, as well as to explore new features of nanoparticle scattering such as the spectral correlation and temporal response of light scattered by nano scatterers, including Mie spheres.
Comment: 8 pages, 2 tables, 4 figures