Optical phase contrast microscopy and cryo-electron microscopy are widely used in the study of cells and proteins, respectively. In both techniques, a specimen imparts a phase shift on the probing particles (photons or electrons), which can be measured using various interferometric techniques.
In this talk I will briefly discuss the physical basics and limits of phase microscopy, and will show ways how to improve on current techniques using wave-front shaping, cavity or quantum enhanced measurements.
I will demonstrate how wave-front shaping can enable phase contrast imaging with optimized sensitivity all across the field of view, and how multi-passing the probe particles through a sample multiple times can be used for high sensitivity / low damage imaging . The latter could potentially allow for cryo-electron microscopy with unprecedented resolution .
 T.Juffmann, B.B.Klopfer, T.L.Frankort, P.Haslinger & M.A.Kasevich, Nature Communications 7, 12858 (2016)
 T.Juffmann, S.A.Koppell, B.B.Klopfer, C.Ophus, R.M.Glaeser & M.A.Kasevich, Scientiﬁc Reports 7, 1699 (2017)