More information from microscopy images by computing power

The first meeting of the Helmholtz Ptychography 4.0 Incubator Project took place at the Helmholtz-Zentrum Berlin (HZB) on November 27, 2019. Seven Helmholtz Centres intend to jointly develop advanced image data analysis and processing methods in order to extract more information from electron and X-ray microscopy images. In particular, the approach will be to use “virtual lenses” to correct imaging errors and thus considerably increase the resolution of images.

Ptychography 4.0 is one of the pilot projects of the Helmholtz Association’s Incubator programme in the field of information and data sciences and is being funded with almost 1.7 million euro by the Initiative and Networking Fund of the President of the Helmholtz Association. The individual participating Helmholtz Centres will be contributing matching funds.

“Ptychography 4.0 is a project in which we are working towards considerably increasing the resolution of electron microscopy as well as X-ray microscopy by correcting imaging errors mathematically”, explains Dr. Markus Wollgarten, head of the CoreLab for Correlative Spectroscopy and Microscopy at the HZB. It should be possible, for example, to display fine surface features of bacteria and viruses with extreme sharpness and to image new materials such as graphene with atomic-level precision without having to resort to expensive corrector optics.

In conventional microscopy, an electron beam or light beam (photons) is sent through the sample. A detector behind it measures the transmitted intensity to obtain an image of the sample. However, valuable information about sample-dependent phase change of the radiation is lost. Ptychography 4.0 will take this information into account mathematically and incorporate it in the analysis. Although this requires data rates in the gigabyte/second range, it allows the sample structure to be reconstructed mathematically with great accuracy. Therefore, many kinds of imaging errors caused by the microscope itself will become practically irrelevant.

The participating partners now want to further develop this approach and optimise the method for routine usage with different types of radiation, such as X-rays, electrons, and XUV light. In particular, image reconstruction is to be accelerated enough that real-time images become feasible.

“As a result of Ptychography 4.0, we will be able to avoid these limiting imaging errors, so that we can dispense with very cost-intensive physical corrector optics. Considerably more research institutes will be able to afford state-of-the-art high-resolution microscopy in the future”, emphasizes Wollgarten.

Participating Helmholtz Centres:
Deutsches Elektronen-Synchrotron (DESY)
Forschungszentrum Jülich (FZJ)
Helmholtz Institute Jena (GSI/HI-Jena)
Helmholtz Zentrum München (German Research Centre for Environmental Health/HMGU)
Helmholtz-Zentrum Berlin (HZB)
Helmholtz-Zentrum Dresden-Rossendorf (HZDR)
Helmholtz Centre for Infection Research (HZI)

Project Coordination:
Adj. Prof. Wolfgang zu Castell
Helmholtz Zentrum München (German Research Centre for Environmental Health/HMGU)
castell@helmholtz-muenchen.de
Prof. Christian Schroer
Deutsches Elektronen-Synchrotron (DESY)
christian.schroer@desy.de

Dr. Gerd Schneider (X-ray microscopy) as well as Ants Finke (IT Department) at HZB are also involved.