  Efficient and broadband forward-scattering is a property of prime importance
for meta-atoms if they are to be used in self-assembled metasurfaces. Strong
contenders include colloidal nanoresonators with tailored multipolar content to
achieve the proper interferences that suppress back-scattering. We consider
dense plasmonic balls composed of more than a hundred silver nanoinclusions.
Numerical simulations provide a full understanding of the role played by
multipole moments in the scattering behavior. They are fabricated using
emulsion drying and characterized optically. Strong and efficient
forward-scattering is demonstrated over the entire visible range. Electric and
magnetic dipole resonances of equal amplitude and phase are evidenced. Such
plasmonic balls could be used as meta-atoms for bottom-up metasurface
applications.
