Major results of the project MICROMOUPE:
1. We advanced the theoretical understanding of interferometric microscopy techniques: We have analyzed phase microscopy techniques based on the information-theoretical concepts of (Quantum) Fisher Information and (Quantum) Cramér-Rao Bounds (Q-CRB). The CRB enabled a quantitative comparison of the measurement precision that is possible using existing imaging techniques, such as phase contrast microscopy, holography, phase-stepping interferometry, interferometric scattering microscopy, coherent bright-field imaging, or darkfield microscopy. The Q-CRB gives an upper limit on the achievable precision and yields a gauge against which all techniques can be compared. Our results can be found in (Maestre et al., Phys. Rev. Appl., 15(2), 024047 (2021)), and in (Dong et al., J. Phys. D.: Appl. Phys., 54,39 (2021)).
2. We demonstrated reconfigurable quantum networks (S. Leedumrongwatthanakun, Nature Photonics, 14, pages139–142(2020).): In collaboration with Prof. Gigan (ENS Paris), we could show that wavefront shaping, in combination with the complex coupling provided within multimode fibers, can enable reconfigurable quantum networks. Specifically, we showed that specific quantum states can be realized at the output of a multimode fiber if the wavefront at the input was shaped appropriately.
3. We demonstrated ponderomotive electron beam shaping (Mihaila et al, Phys. Rev. X 12, 031043 (2022)): In light optics, advanced wavefront shaping techniques have enabled applications in imaging, astronomy, and quantum engineering (see above). In electron optics, on the other hand, wavefront shaping techniques are still in a proof-of-principle state. Within MICRMOUPE, we could show that an electron pulse can be shaped using intense laser pulses. Shaping the laser pulses prior to the interaction with the electrons allowed us to realize programmable, almost arbitrary electron beam shaping. Importantly, electron-light interaction is fully elastic and lossless, which sets it apart from other approaches to wavefront shaping. This realizes new degrees of freedom in electron optics, potentially enabling aberration correction, phase plates for phase microscope, or probe-engineering for ptychography. Note, that wavefront shaping is crucial to achieve the sensitivity limits described in point 1 above.
4. We envisioned a novel microscopy technique, which we call Optical Near-field Electron Microscopy (R. Marchand et al., Phys. Rev. Applied 16, 014008 (2021)). The technique is based on the photo-electric effect and combines the non-invasiveness of light microscopy with the spatial resolution enabled by electron optics. The idea we proposed is now pursued in an EIC-funded project (ONEM, ID 101017902), which we coordinate. The first experimental results already show the potential of the technique for label- and damage-free super-resolution microscopy.
5. We have contributed to designs for the world’s first Multi-pass Transmission Electron Microscope (MPTEM, M. Mankos et al., Advances in Imaging and Electron Physics, 212, 71-86 (2019)). MPTEM promises to reduce the dose-induced damage in electron microscopy by a factor of ~4, which could potentially enable the imaging of single alpha helices using electron microscopy. The prototype we designed is currently manufactured and will soon be installed in the lab of our collaborator Prof. Kasevich (Stanford University).
6. We have developed a setup for fast and efficient fluorescent lifetime microscopy: Our work on optical multi-pass microscopy led to the development of electro-optic crystals that can be used to gate an image with nanosecond resolution. Based on this development we applied for an ERC proof-of-principle grant in order to develop super-resolution fluorescent lifetime imaging. The grant (EOFLIM) is still ongoing, but the first super-resolved FLIM data have been obtained and will be published soon. The technique improves the speed of FLIM by orders of magnitude, and thus also enables volumetric imaging and video-rate live-cell imaging. We believe that this technique provides exciting opportunities for the life sciences and for diagnostics.
7. We have also engaged in an outreach project that communicates science in an artistic way (E de Dios Rodríguez et al, Leonardo, 1-7 (2020)). Our work uses modern technology to image light propagating across everyday objects. Our work was shown in public talks, public installations, and outreach events.
