International Conference on Transparent Optical Networks

High switching rate post-selection free time-bin entanglement in thin-film lithium niobate

Andrea Bernardi, Marcello Bacchi, Marco Clementi, Sara Congia, Francesco Garrisi, A. Martellosio, Marco Passoni, Alexander Wrobel, Federico Andrea Sabattoli, Mattéo Galli, Daniele Bajoni

Published Jul 6, 2025• 0 citations

Publisher

Abstract

Time-bin entanglement is a widely adopted approach for quantum communication because of its robustness against propagation over optical fibers networks. However, certain projective measurements in this encoding scheme necessitate post-selection, introducing a loophole in Bell inequality tests and requiring precise temporal resolution. We present an integrated photonic circuit that certifies time-bin entanglement while eliminating the need of post-selection through a high-speed optical switching mechanism. Implemented using thin-film lithium niobate technology, this device operates at 5 GHz switching rate, enabling high secure key rates. Our results demonstrate a Bell inequality violation exceeding 27 standard deviations, achieved without requiring time resolution at the scale of the time-bin separation.

DOI: 10.1109/icton67126.2025.11125056

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