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arXiv · 2603.24734

Ultra-Short flying-focus

Jérôme Touguet·Igor A. Andriyash·Lucas Rovige·Cédric Thaury
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Abstract

Achromatic flying-focus enables programmable control of intensity peak velocity, with applications in ultrafast optics. However, spatiotemporal coupling inherently elongates ultrashort pulses by introducing frequency-dependent focusing and arrival-time dispersion. We present a theoretical model identifying this pulse-lengthening effect and propose a radially-dependent spectral chirp to compensate for chromatic timing mismatches. Numerical simulations confirm that this approach preserves both pulse duration and programmed flying-focus velocity over extended focal regions. Additionally, dispersive media such as plasmas can naturally mitigate elongation. These results extend achromatic flying-focus techniques to ultrashort pulses, enabling new opportunities in laser--plasma interactions and high-field nonlinear optics.

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Jérôme Touguet, Igor A. Andriyash, Lucas Rovige, Cédric Thaury. 2026-03-25. Ultra-Short flying-focus. https://arxiv.org/abs/2603.24734

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