标题： 布拉格相干调制成像：扩展样品的应变和缺陷敏感单视图 显示英文标题

标题： Bragg Coherent Modulation Imaging: Strain- and Defect- Sensitive Single Views of Extended Samples

摘要： 纳米尺度的异质性（包括尺寸、形状、应变和缺陷）显著影响材料的性能及其功能。 布拉格相干X射线成像方法已成为一种强大的工具，用于在三维细节上研究反应环境中外部刺激对局部材料的响应，从而实现了在纳米尺度上对结构-缺陷-功能关系的探索。 尽管已经取得了对这种关系的理解进展，但由于解决相位问题所需的实验限制，扩展样品的相干成像相对缓慢（通常需要许多分钟）。 在这里，我们开发了布拉格相干调制成像（BCMI），该方法使用调制器来解决相位问题，从而实现对扩展样品的快速局部成像。 由于已知的调制器对于该技术至关重要，我们首先通过实验演示了可以通过标准布拉格相干衍射成像（BCDI）实验中存在的出射波多样性来恢复未知的调制器结构。 然后，我们通过模拟表明，已知的调制器约束足以解决相位问题，并能够实现对扩展样品的单次观测，该观测对缺陷和位错敏感。 我们的结果为BCMI在复杂扩展晶体中应变和缺陷动力学的研究铺平了道路，时间分辨率受限于单个衍射图样的曝光时间。 显示英文摘要

摘要： Nanoscale heterogeneity (including size, shape, strain, and defects) significantly impacts material properties and how they function. Bragg coherent x-ray imaging methods have emerged as a powerful tool to investigate, in three-dimensional detail, the local material response to external stimuli in reactive environments, thereby enabling explorations of the structure-defect-function relationship at the nanoscale. Although progress has been made in understanding this relationship, coherent imaging of extended samples is relatively slow (typically requiring many minutes) due to the experimental constraints required to solve the phase problem. Here, we develop Bragg coherent modulation imaging (BCMI), which uses a modulator to solve the phase problem thereby enabling fast, local imaging of an extended sample. Because a known modulator is essential to the technique, we first demonstrate experimentally that an unknown modulator structure can be recovered by using the exit wave diversity that exists in a standard Bragg coherent diffraction imaging (BCDI) experiment. We then show with simulations that a known modulator constraint is sufficient to solve the phase problem and enable a single view of an extended sample that is sensitive to defects and dislocations. Our results pave the way for BCMI investigations of strain and defect dynamics in complex extended crystals with temporal resolution limited by the exposure time of a single diffraction pattern.