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In any micrograph, the number of detected probe particles is fundamentally limited, either due to finite acquisition times or probe-induced sample damage. How can we optimize the sensitivity of a microscope and maximize the information that can be extracted from each detected probe particle?
We employ cavity enhancement, quantum enhancement, and wave-front shaping techniques to optimize the sensitivity of interferometric imaging techniques. We do so both for electron and for light microscopy.
Thomas Juffmann did his PhD on molecular quantum optics at the University of Vienna. He then moved to Stanford to work on quantum enhanced imaging with electrons and photons. After that, he joined the ENS Paris as an interdisciplinary HFSP fellow working on adaptive optics. In 2013, he started the Quantum Imaging and Biophysics group in a joint venture between the Faculty of Physics and the MFPL.
Passing probe particles through a sample multiple times can increase the signal to noise per detected particle. We demonstrated full field cavity enhanced microscopy with light , and showed theoretically , that the same principle could enable cryogenic electron microscopy at unprecedented low damage levels.
 Multi-pass microscopy; T. Juffmann, B. B. Klopfer, T. L.I. Frankort, P. Haslinger & M. A. Kasevich; Nature Communications, Vol. 7, 12858 (2016)
 Multi-pass transmission electron microscopy; T. Juffmann, S. A. Koppell, B. B. Klopfer, C. Ophus, R. M. Glaeser & M. A. Kasevich; Scientific Reports, Vol. 7, 1699 (2017)
Phase microscopy is based on interfering a signal wave with a reference wave. Depending on local, sample induced phase-shifts, the sensitivity of the most common techniques locally goes to zero. Local Wave-front shaping for Phase Imaging uses adaptive optics to maximize sensitivity all across the field of view.
 LowPhi (Local Optimization of Wave-fronts for high sensitivity PHase Imaging); T. Juffmann, A. de los Rios Sommer, S. Gigan, arXiv:1809.02993v1 (2018)