Diffraction on non-plane gratings irradiated by non-planar waves

An application of the boundary integral equation method (MIM), which is developed for plane relief gratings and plane waves, to diffraction of cylindrical/spherical/gaussian waves by plane gratings or plane/non-planar waves by concave/convex gratings is described. Efficiency calculations for curved gratings irradiated by non-planar waves are performed using the respective discretization problems implemented in PCGrate® codes using the MIM. The dependence on the number of plane waves/sections and radii of grating and wave front shapes are demonstrated for high-conductive lamellar, sinusoidal and sawtooth groove profiles in 0th and −1st diffraction orders and in the TE/TM polarization. The influence of resonance angles and partitions by plane waves/sections on the exact solutions of 2D and 3D (conical) diffraction grating problems is discussed.