Enhanced accuracy in fast-Fourier-based methods for full-vector modal analysis of dielectric waveguides

A nonconventional variant of a full-vector fast-Fourier-transform-based mode solver is presented to analyze arbitrarily shaped optical dielectric waveguides. The key point of the proposed method for the improvement of the accuracy is to consider a higher number of discretization points in the space domain than Fourier coefficients for the description of the field components. Strongly guiding structures have been analyzed showing excellent accuracy with low computational effort compared to previous approaches