Szwaj, C. Bielawski, S. Evain, C. Gerth, C. Jalali, B. Roussel, E. Steffen, B. JACoW Publishing Geneva, Switzerland 2673-5350 978-3-95450-241-7 10.18429/JACoW-IBIC2022-TH1C3 English 536-539 laser electron experiment polarization FEL Contribution to a conference proceedings 2022 2022-12 https://doi.org/10.18429/JACoW-IBIC2022-TH1C3 https://jacow.org/ibic2022/papers/th1c3.pdf Recording electric field evolutions in single-shot and with sub-picosecond resolution is required in electron bunch diagnostics, and THz applications. A popular strategy consists of transferring the unknown electric field shape onto a chirped laser pulse, which is eventually analyzed. The technique has been investigated and/or been used as routine diagnostics at FELIX, DESY, PSI, Eu-XFEL, KARA, SOLEIL, etc. However fundamental time-resolution limitations have been strongly limiting the potential of these methods. We review recent results on a strategy designed for overcoming this limit: DEOS [1] (Diversity Electro-Optic Sampling). A special experimental design enables to reconstruct numerically the input electric signal with unprecedented temporal resolution. As a result, 200 fs temporal resolution over more than 10 ps recording length could be obtained at European XFEL - a performance that could not be realized using classical spectrally-decoded electro-optic detection. Although DEOS uses a radically novel conceptual approach, its implementation requires few hardware modifications of currently operating chirped pulse electro-optic detection systems.