  Under the influence of the material environment, electromagnetic fields in
the near-field regime exhibit quite different nature from those in the
far-field free space. A coupled state of an electromagnetic field with an
electric or magnetic dipole-carrying excitation is well known as a polariton.
Such a state is the result of the mixing of a photon with an excitation of a
material. The most discussed types of polaritons are phonon-polaritons,
exciton-polaritons, and surface plasmon-polaritons. Recently, it was shown that
in microwaves strong magnon-photon coupling can be achieved due to
magnetic-dipolar-mode (MDM) vortices in small thin-film ferrite disks. These
coupled states can be specified as MDM-vortex polaritons. In this paper we
study properties of MDM-vortex polaritons. We show that MDM-vortex polaritons
are characterized by helicity behaviors. For the observed frequency splits of
MDM resonances there are different-type helicities. In the split-resonance
states one has or localization, or cloaking of electromagnetic fields. We
analyze numerically a variety of the field topological structures of MDM-vortex
polaritons and give theoretical insights into the possible origin of such
topologically distinctive states. The shown properties of MDM-vortex polaritons
can be useful for realization of novel microwave metamaterial structures and
near-field sensing applications.

Optics