Upcoming Talks

Scattering of light in complex samples, such as biological tissues or fog, renders most samples opaque and presents a fundamental challenge for conventional optical imaging. This is a problem of great practical importance, limiting applications from deep-tissue microscopy to automotive sensing and astronomy [1-2]. However, although seemingly random, scattering is a deterministic process, meaning that, in principle, the distortion can be undone and a clear image can be recovered. The main challenge is how to find (and apply) the specific complex correction needed in a non-invasive and practical way. Very recent works have demonstrated that this is indeed achievable in practice - through visually-opaque samples, flexible fibers, and even around corners - by either physically correcting the wavefronts using spatial light modulators (SLMs) [3], or by purely computational reconstruction [4-6]. I will review the principles and limitations of the state of the art approaches for undoing random scattering, which exploit the inherent correlations of scattered ‘speckle’ patterns, without relying on ‘guide stars’ or training data. Specifically, I will explain how decomposion of the scattering matrix or image-guided optimization can lead to the correction wavefront. If time permits I will explain how dynamic scattering can be tackled [6]. References [1] Optics: Super vision, Z.Merali, Nature 518, 158 (2015). [2] Imaging in complex media, J.Bertolotti, O.Katz, Nature Physics, 18, 1008–1017 (2022) [3] Guidestar-free image-guided wavefront shaping, T.Yeminy, O.Katz, Science Advances, 7, 21 (2021). [4] Image-guided Computational Holographic Wavefront Shaping, O.Haim, J.Boger-Lombard, O.Katz, Nature Photonics :2305.12232 (2023). [5] Noninvasive megapixel fluorescence microscopy through scattering layers by a virtual incoherent reflection matrix, G.Weinberg, E.Sunray, O.Katz, Science Advances, 10, 47 (2024). [6] Matrix-based imaging through dynamic scattering, E.Sunary, G.Weinberg, B.Laufer, O.Katz, Nature Communications, 16, 9413 (2025)

Ori Katz is a Professor of Applied Physics at the Hebrew University of Jerusalem. His lab develops physics-based methods for imaging, sensing, and controlling waves in complex media. Beyond imaging, his work on time-reversed lasing was selected as a Top 10 Breakthrough of 2022 by Physics World. He earned his Ph.D. in physics from the Weizmann Institute of Science, where he worked on ultrafast optics, quantum coherent control, and nonlinear microscopy and spectroscopy. He is a recipient of ERC Starting and Consolidator Grants and the Krill Prize.