Numerical studies of multilayer gratings using the method of eigenvectors

The method of eigenvectors has been adapted for numerical studies of lamellar multilayer gratings with a partially etched multilayer stack (phase multilayer gratings). Unlike the existing modal and differential methods, this method can be applied to thick multilayer gratings with a small grating period, and also to the case of grazing incidence of radiation. For the case of soft X-rays, the reciprocity curves have been obtained for different numbers of etched bilayers in a multilayer structure using this method. The numerical calculations based on the proposed method were used to interpret the experimental data on diffraction properties of the Ni/C multilayer grating.