Analysis of a polarization converter using a full-vectorial fundamental alternating-direction implicit beam-propagation method

A simplified algorithm for the full-vectorial alternating-direction implicit beam-propagation method (FVADI-BPM) is developed using a fundamental scheme. The resultant equations are reduced to those with only two spatial derivatives for a polarization coupling effect in the right-hand sides, while the conventional FV-ADI-BPM includes four derivatives for a specific polarization and four for a polarization coupling effect. We assess the performance, when analyzing a z-variant structure with a polarization coupling effect. The present method is found to yield the result identical to that from the conventional method, reducing the computation time by about 35%.