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

TL;DR

This paper introduces a comprehensive full-vector angular spectrum method that accurately and efficiently models electromagnetic diffraction for arbitrary incident fields, including reflection and transmission effects, significantly speeding up optical system design.

Contribution

The paper presents a novel full-vector angular spectrum approach that improves accuracy and efficiency in electromagnetic diffraction calculations, addressing previous limitations in incident field modeling.

Findings

Achieves rapid computation times of a few seconds for symmetric systems.

Handles arbitrary incident fields with precise polarization projection.

Inherently models reflection and transmission at dielectric interfaces.

Abstract

Numerous vector 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 vector methods is challenging, especially with not well-defined incident fields. Here, we propose a full-vector angular spectrum method for accurate, efficient, robust diffraction computation, allowing truly arbitrary incidence by precisely modeling the projection rule among Cartesian polarization components. We address a prior oversight, that the longitudinal electric field's projection onto the diffracted field was insufficiently considered. 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 optical design via faster input-output mapping in optimization algorithms.