  An opalic plasmonic sample, constituted by a hexagonal arrangement of
metallized silica spheres, presents remarkable optical properties due to the
mixing of periodic arrangement and singularities at the sphere touching points.
It is therefore an interesting candidate for exploiting the excitation of both
localized and propagating surface plasmons. Several channels of excitation
based on these properties or exploiting a certain level of disorder are
evidenced, opening new routes for the efficient excitation of plasmons on a
wide spectral range. The versatility of such hybrid system is evidenced in the
context of two complementary experiments: specular reflective spectrometry and
photoemission electron microscopy. Both techniques offer different points of
view on the same physical phenomenon and the link between them is discussed.
Such experiments evidence the opportunities offered by these 2D hybrid
materials in the context of nanophotonics.
