  Surface lattice resonance supported on plasmonic nanoparticle arrays enhances
light-matter interactions for applications such as photoluminescence
enhancement. The photoluminescence process is enhanced through confining light
beyond the diffraction limit and inducing stronger light-matter interaction. In
this work, the absorption mechanisms of plasmonic nanoparticle arrays embedded
with photoluminescent absorbers are analyzed. A modified coupled-mode theory
that describes the optical behavior of the surface lattice resonance was
developed and verified by numerical simulations. Based on the analytical model,
different components of the absorption contributed by the nanoparticles and the
absorbers as well as the resonant properties of each of the components are
identified. The origin of difference in resonant behavior with different
materials is also discovered by exploring the nearfield characteristics of
surface lattice resonance composed with a variety of materials.
