Ptychography is a coherent diffractive imaging technique that can determine how an electron wave is transmitted through an object by probing it in many small overlapping regions and processing the diffraction data obtained at each point. The resulting electron transmission model describes both phase and amplitude changes to the electron wave. Ptychography has been adopted in transmission electron microscopy (TEM) in recent years following advances in high speed direct electron detectors and computer algorithms which now make the technique suitable for practical applications. Its ability to retrieve quantitative phase information at high spatial resolution makes it a plausible alternative or complement to electron holography. Furthermore, unlike off-axis electron holography, it can provide phase information without an electron bi-prism assembly or the requirement of a minimally structured region adjacent to the region of interest in the object. However, it does require a well calibrated scanning TEM and a well-managed workflow to manage the calibration, data acquisition and reconstruction process to yield a practical technique. Here we detail this workflow and highlight how this is greatly assisted by acquisition management software. Through experimental data and modelling we also explore the similarities and differences between high resolution ptychography and electron holography. Both techniques show a dependence of the recovered phase on the crystalline orientation of the material which is attributable to dynamical scattering. However, the exact nature of the variation differs reflecting fundamental expectations, but nonetheless equally useful information is obtained from electron holography and the ptychographically determined object transmission function.

中文翻译：

---

高分辨率电子印刷术的实际实施以及与离轴电子全息术的比较

Ptychography 是一种相干衍射成像技术，它可以通过在许多小的重叠区域中探测物体并处理在每个点获得的衍射数据来确定电子波如何穿过物体。由此产生的电子传输模型描述了电子波的相位和幅度变化。近年来，随着高速直接电子检测器和计算机算法的进步，透射电子显微镜 (TEM) 已采用 Ptychography，现在该技术适用于实际应用。它以高空间分辨率检索定量相位信息的能力使其成为电子全息术的合理替代或补充。此外，与离轴电子全息术不同的是，它可以提供相位信息，而无需电子双棱镜组件，也不需要与目标感兴趣区域相邻的最小结构区域。然而，它确实需要校准良好的扫描 TEM 和管理良好的工作流程来管理校准、数据采集和重建过程，以产生实用的技术。在这里，我们详细介绍了这个工作流程，并强调了采集管理软件如何极大地帮助了它。通过实验数据和建模，我们还探索了高分辨率 ptychography 和电子全息术之间的异同。两种技术都显示了恢复相对材料晶体取向的依赖性，这可归因于动态散射。然而，变化的确切性质反映了基本预期，