Polygon-based unified Fourier-modal approach for diffractive-optics simulations
Phys. Rev. A 112, 043511 – Published 9 October, 2025
DOI: https://doi.org/10.1103/n2qj-l886
Abstract
In this article, we derive a theoretical formalism that unifies the rigorous coupled wave analysis and the dynamical diffraction theory. Based on this formalism, we design a computational approach for the diffraction calculation for the nanoscale lamellar gratings with an arbitrary line profile shape. In this approach, the gratings line profile is approximated as a polygon. This proves to be convenient since such an approach does not rely on the geometry model of the grating. We test the proposed approach against other computational theories and a synchrotron scattering experiment.
