A field-based numerical method for three-dimensional analysis of optical waveguide discontinuities

A field-based numerical method for simulation of field scattering at discontinuities along three-dimensional optical waveguides of arbitrary index profiles is presented. Different from the previous work based on directly diagonalizing the characteristic matrices, we developed a robust and efficient iterative scheme by using an improved Neumann series. Superb performance of the scheme in terms of accuracy and efficiency is demonstrated and verified.