An economic method for the solution of the scalar wave equation for arbitrary shaped optical waveguides

The discrete sine method, in which the basis functions consist of sine functions defined on a set of parallel discretization lines, is discussed. The method is a combination of a scalar version of the finite difference method and sine method. The choice of the basis set leads for the eigenvalue equation to be solved, to a sparse matrix with a small bandwidth. As a consequence, the propagation constant of guided modes in optical waveguides may be calculated with short computation times and low storage needs. Results obtained with the method for three different wave guiding structures are compared with those of other methods.