• self-assembly;
  • SERS;
  • optical vortex;
  • photonic-plasmonic resonances;
  • magnetic field enhancement
Thumbnail image of graphical abstract

Compact metallo-dielectric hybrid clusters with subwavelength dimensions are fabricated by template guided self-assembly. Elastic and inelastic scattering spectroscopy and electromagnetic simulations reveal that hybrid clusters comprising TiO2 nanoparticles on top of a cluster of strongly coupled gold nanoparticles harness synergistic electromagnetic interactions between the building blocks. This results in a boost of the peak electric field intensity and a redistribution of the field in the ambient medium. The complex phase landscape in the clusters features optical vortices that enhance the magnetic field.