Direct single-shot imaging of time-resolved terahertz vector fields

J. Lafreniere-Greig; J. E. Nkeck; X. Ropagnol; G. Gandubert; Salim Hmidi; O. Brincoveanu; O. -G. Simionescu; E. Abraham; R. Tudor; F. Blanchard

arXiv · 2606.14011

Direct single-shot imaging of time-resolved terahertz vector fields

J. Lafreniere-Greig·J. E. Nkeck·X. Ropagnol·G. Gandubert·Salim Hmidi·O. Brincoveanu·O. -G. Simionescu·E. Abraham·R. Tudor·F. Blanchard

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Abstract

We demonstrate direct single-shot retrieval of the full in-plane vector field of broadband terahertz waves using electro-optic sampling. Implemented with a circularly polarized optical probe and polarization-sensitive camera, the method overcomes the projection constraints of conventional electro-optic sampling and enables direct time-domain reconstruction of transverse vector fields without Fourier-domain inversion or sequential polarization analysis. We experimentally validate the approach through spatiotemporal imaging of linear, circular, azimuthal and radial terahertz fields generated by polarization-engineered silicon metamaterials. The measurements reveal ultrafast time-resolved vector-field dynamics inaccessible to conventional scalar detection, including helicoidal field rotation within a single optical cycle and the spatiotemporal evolution of structured polarization topologies. Beyond structured-field imaging, we demonstrate single-scan vector-field spectroscopy through measurements of quartz birefringence and broadband terahertz waveplate performance. More broadly, this work transforms electro-optic sampling from a projection-based measurement into a vector-resolved imaging and spectroscopy platform for structured electromagnetic fields.

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J. Lafreniere-Greig, J. E. Nkeck, X. Ropagnol, G. Gandubert, Salim Hmidi, O. Brincoveanu, O. -G. Simionescu, E. Abraham, R. Tudor, F. Blanchard. 2026-06-12. Direct single-shot imaging of time-resolved terahertz vector fields. https://arxiv.org/abs/2606.14011

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