硬x射线同轴相衬成像的相位恢复

Phase retrieval for hard x-ray in-line phase contrast imaging

基于角谱的概念 ,分析了硬x射线同轴相衬成像过程 ,在传统相位恢复算法GS算法的基础上 ,提出了基于角谱传播的相位恢复算法——迭代角谱法 (IASA) ,并利用数值法模拟研究了相衬成像和相位恢复过程 ,从理论上验证了这一相位恢复算法 .

Since hard x-ray in-line phase-contrast imaging is based on Fresnel diffraction of x-ray, we propose to make phase retrieval calculations between arbitrary planes interrelated through the Fresnel domain. The calculation of the free space propagation is based on the angular spectrum approach, which can be used with Gerebberg-Saxton algorithm for phase retrieval. We call this method the iterative angular spectrum approach. The new method is tested on simulated images in the case of uniform illumination and is demonstrated to be efficient for phase retrieval.