26. February 2019

Stefan Witte

Spectroscopic lensless imaging: from visible to soft-X-ray wavelengths

Vrije Universiteit Amsterdam / Amsterdam, The Netherlands

Computational imaging is an elegant approach to microscopy, in which the image formation is achieved using computer algorithms rather than optical components. This approach can be used either to obtain images with completely lensless systems, or to enhance the capabilities of lens-based systems to beyond the basic hardware capabilities in terms of resolution, contrast and sensitivity.

I will discuss our ongoing efforts to develop computational imaging systems for 3D and phase contrast microscopy using visible light, as well as our research on high-resolution spectrally resolved soft-X-ray microscopy based on high-harmonic generation sources. Furthermore, I will discuss various applications of lensless imaging, from quantitative bio-imaging to element-resolved characterization of nanostructures.

Short Bio
Stefan Witte received his PhD in 2007 from the Vrije Universiteit Amsterdam, for work on intense ultrafast laser development and precision spectroscopy with Prof. Kjeld Eikema. He did postdoctoral work at on nonlinear microscopy and biomedical imaging (Vrije Universiteit) with Prof. Marloes Groot, and on ultrafast electron dynamics and lensless imaging with high-harmonic sources (JILA, University of Colorado) with Profs. Henry Kapteyn and Margaret Murnane.
Since 2014 he leads the EUV Generation and Imaging research group at the Advanced Research Center for Nanolithography (ARCNL), and he has a tenured position as assistant professor at the Vrije Universiteit Amsterdam. His research interests include novel imaging techniques for complex nanostructures, coherent diffractive imaging with visible and EUV radiation, high-harmonic generation and its applications, and advanced laser development for plasma experiments. He has received among others an NWO Veni grant and an ERC Starting grant for the development of lensless imaging technology.