Use of Kramers-Kronig relation in phase retrieval calculation in X-ray spectro-ptychography
Use of Kramers-Kronig relation in phase retrieval calculation in X-ray spectro-ptychography
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DOI：
10.1364/oe.25.008593
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发表时间：
2017-04-17
期刊：
影响因子：
3.8
通讯作者：
Takahashi, Yukio
中科院分区：
文献类型：
--
作者：
Hirose, Makoto;Shimomura, Kei;Takahashi, Yukio
相干衍射成像（CDI）是一种利用迭代定相方法从物体的衍射强度重建复值图像的方法。X射线重叠关联成像是一种使用X射线的CDI扫描类型，使我们能够可视化扩展样本的复杂透射函数。在这里，我们建议使用的Kramers-Kronig关系（KKR）作为一个额外的约束条件，在相位检索算法的多能量X射线重叠关联使用一个特定的元素的吸收边缘。数值模拟表明，改进后的KKR算法提高了算法的收敛速度。我们在SPring-8的原理验证实验中成功地证明了它的实用性。本算法是特别有用的成像X射线吸收精细结构的一个特定的元素埋在厚的样品通过硬X射线光谱重叠关联。(C)2017美国光学学会
Coherent diffraction imaging (CDI) is a method for reconstructing the complex-valued image of an object from diffraction intensities by using iterative phasing methods. X-ray ptychography is a scanning type of CDI using X-rays, allowing us to visualize the complex transmission function of an extended specimen. We here propose the use of the Kramers-Kronig relation (KKR) as an additional constraint in phase retrieval algorithms for multiple-energy X-ray ptychography using the absorption edge of a specific element. A numerical simulation showed that the speed of convergence was increased by using the improved algorithm with the KKR. We successfully demonstrated its usefulness in a proof-of-principle experiment at SPring-8. The present algorithm is particularly useful for imaging X-ray absorption fine structures of a specific element buried within thick samples by hard X-ray spectro-ptychography. (C) 2017 Optical Society of America