Generic full-vector angular spectrum method for calculating diffraction of arbitrary electromagnetic fields

Numerous angular spectrum methods have been presented to model the vectorial nature of diffractive electromagnetic field, facilitating optical field engineering in polarization-related and high numerical aperture systems. However, balancing accuracy and efficiency in state-of-the-art methods is challenging. Here, we propose a full-vector angular spectrum method for accurate, efficient, robust diffraction computation, allowing truly arbitrary incidence by precisely modeling vector plane-wave. Notably, our method inherently handles reflection and transmission at dielectric interfaces, which can be viewed as k-space filters. For rotationally symmetric system, it achieves unprecedented computation times of a few seconds, speeding up input-output mapping in optimization algorithms.