Fast-Fourier-based three-dimensional full-vectorial beam propagation method

An accurate and highly efficient fast-Fourier-based full-vectorial beam propagation method (BPM) with perfectly matched layer absorbing boundary conditions is presented. Full vectorial results obtained for highly guiding z-variant structures, such as a spot size converter and a Y-branch in rib technology, show that accurate results can be obtained with reduced computational effort, thus making this technique an interesting alternative to other existing BPM strategies.