Reflectivity behavior of two-dimensional ordered array of metallodielectric composite particles at large incidence angles

Optical reflectance of a two-dimensional (2D) metallodielectric (MD) photonic crystal composed of hexagonal array of close-packed silver-shell polystyrene-core composite particles has been studied at off-normal incidence under both P and S polarizations. A dramatic change in reflectivity behavior of the 2D MD film from a 2D colloidal crystal template and a homogeneous silver film has been observed. The phenomenon of strong reflectance bands of the 2D MD film was explained as a selective coupling of the incident light with surface plasmon of the 2D textured structure via the 2D grating.