Generalized source method in curvilinear coordinates for 2D grating diffraction simulation

•Efficient numerical method for simulation of the light diffraction on multilayer metal-dielectric crossed gratings with smooth corrugation interfaces.•The method is based on grating corrugation interface representation in curvilinear space.•The concept of effective metric sources is extended for crossed gratings.•Method parallelization on graphical processing units is demonstrated.

The article presents a curvilinear coordinate Fourier space integral method for linear optical rigorous grating diffraction simulation in 3D (crossed grating diffraction). The presented formulation extends our previous work on a related method for 1D periodic grating diffraction. Following this previous work we exploit a concept of the generalized metric sources to efficiently solve the Maxwell׳s equations. The article provides a general description of the method together with a detailed formulation and analysis of sinusoidal corrugation crossed grating diffraction.