Analysis of Highly Conducting Lamellar Gratings With Multidomain Pseudospectral Method

In this paper, multidomain pseudospectral (MDPS) method is adopted to analyze the diffraction of electromagnetic waves by the metallic lamellar grating. This method is based on applying a spectral accuracy at the Chebyshev collocation points to the spatial derivatives in Helmholtz equation, and then dividing the computational domain into nonoverlapping subdomains. Finally, the physical boundary conditions at the subdomain interfaces enforce the subdomains to a global system. The numerical examples for 1-D binary gratings composed of different highly conducting materials are presented. The validity of results by MDPS is compared with commonly used rigorous coupled wave analysis for TM polarization. The numerical evidence shows that the developed method has better stability and higher efficiency.