Wang Wei, Zhang Xin, Meng Qingyu, Wang Dong
Opt Express. 2021 Feb 1;29(3):2953-2970. doi: 10.1364/OE.408524.
Occulters with multiple-disk structure are commonly used for mitigating the diffraction light from specific incident angles in external coronagraphs. In the design phase of coronagraphs, it is of great importance to calculate the diffraction propagation of the occulters with high accuracy and high efficiency. In this paper, an analytical method is proposed for the diffraction analysis of multiple-disk occulters based on uniform boundary wave (BDW) diffraction theory. First, an analytical propagator with Fresnel functions is derived for single-disk case, of which the accuracy and efficiency are demonstrated by a numerical example. Then it is proved that the propagator in multiple-disk case was just the iterative use of the single-disk one when neglecting the gradient diffraction term. The analytical propagator presents much improvement on simplification and efficiency compared to former numerical propagators, and hence, is of great significance to future external coronagraph design and analysis.
具有多盘结构的遮光器通常用于减轻外部日冕仪中特定入射角的衍射光。在日冕仪的设计阶段，高精度、高效率地计算遮光器的衍射传播非常重要。本文提出了一种基于均匀边界波（BDW）衍射理论的多盘遮光器衍射分析方法。首先，针对单盘情况推导了一个带有菲涅耳函数的解析传播子，并通过数值示例证明了其精度和效率。然后证明了在忽略梯度衍射项时，多盘情况下的传播子只是单盘传播子的迭代使用。与以前的数值传播子相比，该解析传播子在简化和效率方面有很大改进，因此对未来的外部日冕仪设计和分析具有重要意义。
