  High refractive index dielectric nanoparticles have provided a new platform
for exotic light manipulation through the interference of multipole modes. The
Kerker effect is one example of a Huygens source design. Rather than exploiting
interference between the electric dipole and magnetic dipole, as in many
conventional Huygens source designs, we explore Kerker-type suppressed backward
scattering mediated by the dominant electric dipole, toroidal dipole and
magnetic quadrupole. These modes are provided by a designed and fabricated CMOS
compatible ultra-thin Silicon nanodisk metasurface with a suppressed magnetic
dipole contribution, and verified through multipole decomposition. The
non-trivial substrate effect is considered using a semi-analytical transfer
matrix model. The model successfully predicts the observed reflection dip. By
applying a general criterion for constructive and destructive interference, it
is shown that while constructive interference occurs between the electric and
toroidal dipole contributions, the experimentally observed suppressed backward
Kerker-type scattering arises from the destructive interference between
backward scattered contributions due to the total electric dipole and the
magnetic quadrupole. Our study paves the way towards new types of Huygens
sources or metasurface design, such as for peculiar transverse Kerker
scattering.
