Speaker
Description
Laser-wakefield accelerators (LWFAs) have demonstrated the ability to generate high-quality, monoenergetic electron beams. Yet, efforts to achieve higher electron energies are hampered by electron dephasing and beam diffraction. One promising approach to mitigating these limitations is the use of structured light to control the on-axis propagation velocity within LWFAs. This method promises an improved balance of extended acceleration distances and strong accelerating gradients.
In this talk, we report the first experimental observation of wakefields driven by such structured-light beams as well as the first experimental evidence of the mitigation of dephasing in electron acceleration. Spatiotemporally engineered laser pulses are focused using a specialized mirror to produce a quasi-Bessel beam, and the resulting wakefields are directly measured using femtosecond relativistic electron microscopy. We experimentally demonstrate control over the on-axis propagation velocity of the wakefield and follow its evolution throughout the focal region. We investigate how targeted spatiotemporal modifications affect both the wakefield structure and its propagation velocity. Finally, we present the first successful acceleration of electrons using these wakefields, demonstrating partial mitigation of dephasing.
[1] C. Caizergues et al. “Phase-locked laser-wakefield electron acceleration,” Nat. Photonics. 14, 8 (2020)
[2] J.P. Palastro et al. “Dephasingless laser wakefield acceleration,” Phys. Rev. Lett. 124, 134802 (2020)
[3] A. Liberman et al.,“Direct Observation of a Wakefield Generated with Structured Light,” Nat. Commun. 16, 10957 (2025)
[4] A. Liberman et al.,“First Electron Acceleration in a Tunable-Velocity Laser Wakefield,” under review. (https://arxiv.org/abs/2509.21098)
[5] A. Liberman et al.,“Probing Flying-Focus Wakefields,” under review. (https://arxiv.org/abs/2510.16950)
[6] A. Liberman et al., “Use of spatiotemporal couplings and an axiparabola to control the velocity of peak intensity,” Opt. Lett. 49, 814-817 (2024)
| Working group | WG1 |
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