Fast numerical method for modelling one-dimensional diffraction gratings

Based on the generalised source method, a new method for calculating the light diffraction on one-dimensional dielectric diffraction gratings with an arbitrary profile is proposed. The method is an alternative to the widely used Fourier modal method because it possesses the same possibilities in defining different grating profiles; however, it has a significant advantage in calculating complex-shaped gratings because it requires many fewer mathematical operations. The applicability of the method is shown by comparing the calculation results by this method with the results obtained by the conventional methods of light diffraction calculation on the gratings.