Next generation microscopy methods - Novel lensless imaging approaches

Microscopic imaging in the extreme ultraviolet spectral regime calls-out for novel imaging methods due to the high absorption of all optical components. After removing the imaging optics, which is usually between object and detector, the far-field diffraction pattern can be recorded. Using coherent light for the illumination the objects complex-valued transmission function can be numerically retrieved from the diffraction pattern. This powerful technique is called coherent diffraction imaging (CDI) and underlay some restrictions regarding the objects extend. Using overlapping illumination spots, and therefore many slightly changing diffraction patterns, CDI gets extended to ptychography to enable the reconstruction of arbitrarily large objects and provide detailed information about the illumination function. We focus on developing and benchmarking reconstruction algorithms for CDI and ptychography to image artificial and biological objects with high resolution and using lensless imaging methods for characterizing the spatial energy distribution and coherence of novel XUV-sources.

Our research interests regarding these techniques are:

• Development/improvement/benchmarking of numerical reconstruction frameworks
• Nanoscale imaging of artificial or biological samples
• Source characterizations based on ptychographic reconstructions or diffraction analysis