Method Development of X-Ray Ptychography: Towards High-Resolution and High-Throughput Coherent Imaging

Yudong Yao, Argonne National Laboratory
Collection of ptychography imaging dataset

Collection of a ptychographic imaging data set in the simplest single-aperture configuration. (a) Coherent illumination incident from the left is locally confined onto an area of the specimen. A detector downstream of the specimen records an interference pattern. (b) The specimen is shifted (in this case, upwards) and a second pattern is recorded. Note that regions of illumination must overlap with one another to facilitate ptychographic shift-invariance constraint. (c) A whole ptychographic data set uses many overlapping regions of illumination. (d) The entire data set is four-dimensional: for each 2D illumination position (x , y), there is a 2D diffraction pattern (kx, ky).

Credit: 22sm22, Wikipedia

X-ray ptychography has become a widely used imaging technique to view internal structures of samples at nanoscale resolution. As a scanning variant of coherent diffraction imaging, ptychography doesn’t put a limit on the imaging field of view. However, its potential application, such as large field-of-view imaging and three-dimensional imaging, is still limited due to the low throughput because of the high coherent flux requirement and the scanning mechanism. Advanced method development and algorithm improvement are therefore desired to accelerate both data acquisition and data processing speed while maintaining spatial resolution. In this talk, I will introduce the developed broadband ptychography and multi-beam ptychography methods which provide efficient ways to increase ptychography data acquisition speed. In addition, I will discuss the application of the deep learning approach for accelerating the data processing speed for coherent diffraction imaging, including ptychography.

Zoom Link: