  An efficient surface integral equation-based method is proposed for the
analysis of electromagnetic scattering from multilayered media containing
complex periodic inclusions. The proposed method defines equivalent currents at
the interfaces between layers in order to eliminate the need to compute the
layered medium Green's function. Hence, the background medium in a given layer
can be treated as a homogeneous unbounded medium for which the computation of
the Green's function for an infinite doubly periodic array is sufficient. The
resulting method-of-moments interaction matrix has a block tridiagonal
structure, which leads to computational complexity proportional to the number
of layers for both matrix filling and solution. When all layers are identical,
the filling time essentially reduces to that of a single layer, and the
interaction matrix has a Toeplitz structure. Numerical results are provided for
the reflectivity of multilayered periodic arrays of spherical silver
core-silica shell nanoparticles, excited by a plane wave at optical
frequencies. Comparisons with results obtained with an FDTD-based commercial
software validate the accuracy and efficiency of the proposed method.
