Wave scattering from periodic multilayer structures

The computation of single gratings lead to the analysis of the whole structure. Multimode interaction between the scatterers dramatically complicates the theoretical model. If the angle between the gratings rulings is not equal to zero then the problem becomes vector one and therefore, two-dimensional Floquet bases in an oblique coordinate system are used. Then, some auxillary algorithms that significantly simplify the computation procedure by reducing the main problem to set of subproblems, which are analyzed in the one dimensional basis, are considered. The common concepts of such an approach are presented by an example of two-layer grating array.