  Peculiar ring gap modes on the surface of disk close to the metallic thin
film are excited in the visible light regime. We apply plasmon hybridization
method to illustrate the ring gap modes arising from the interaction between
localized disk plasmons and continuum surface plasmons, which cannot be easily
excited by the plane wave with polarization parallel to the film interface. In
the coupled system, the hybrid modes energy and the surface charge distribution
of nanoparticle are investigated both in simulation and hybridization method,
showing consistence with each other. The excitation of ring gap modes provides
further insight into strong coupling of the plasmon and the design of novel
nanostructures.
