Microwave seminar | 13 August 2026

Terahertz radiation can penetrate many opaque materials while remaining non‑ionizing, but standard amplitude‑based imaging fails to reveal subtle structural details. Phase retrieval offers a way out, yet conventional interferometric methods are notoriously difficult to align, demand expert operators, and struggle in the THz range due to weak sources and low detector sensitivity. This review tackles these obstacles head‑on. It provides a clear, practice‑oriented guide to hardware selection and measurement strategies, compares the most common multi‑plane iterative algorithms, and shows how to tailor them for different priorities—be it resolution, speed, or working with small or saturated detectors. The authors also map the entire application landscape, from biology and medicine to industrial inspection and energy, illustrating how phase imaging can handle everything from flat samples to three‑dimensional objects. The result is a comprehensive resource that empowers researchers to deploy phase retrieval reliably outside specialized labs.

Main paper/arXiv, related to the seminar

Tian, Y., Chen, X., Zhang, Z., Yan, Q., Liu, Y., Deng, C., Wan, M., Li, J., Zhang, X., Rong, L., Tsiplakova, E., Petrov, N., Wang, X., Zhu, L., Hu, M. and Zhang, Y., “Terahertz imaging technology: progress and applications,” Opto-Electronic Technol. 2(1), 250009 (2026). https://doi.org/10.29026/oet.2026.250009

Tsiplakova, E. G., Kumar, V., Valzania, L., Gigan, S., Mukherjee, P., Chernykh, A. V, Liu, C., Krasnikov, D. V, Burdanova, M. G., Li, L., Tian, H., Mounaix, P. and Petrov, N. V., “Terahertz phase imaging by single-beam multiple-intensity phase retrieval: a review,” Light Sci. Appl. 15, 1–35 (2026, accepted, at the proofs revision stage).
http://doi.org/10.1038/s41377-026-02348-9