Fast hybrid method for modeling scattering from doubly periodic dielectric structure in 3-D

In this paper, we present an efficient hybrid method based on finite element (FE) and rigorous coupled wave analysis (RCWA) to model scattering from 3-D doubly periodic dielectric structures. The mode expansion technique is used as boundary truncation scheme. This scheme allows truncation boundaries to be placed close to dielectric grating, thus significantly reduces the size of the problem. Comparisons with finite element/boundary integral method, as well as, FE/RCWA with perfectly matched layer (PML), will be given for accuracy validation.