Year: 2026
Type: article
Abstract: Bright harmonic radiation from relativistically oscillating laser plasmas offers a direct route for generating extreme electromagnetic fields. Theory predicts that under optimized conditions, the plasma medium can support strong spatiotemporal compression of laser energy in a coherent harmonic focus (CHF), delivering intensity boosts many orders of magnitude greater than the incident driving laser pulse 1–4 . Although diffraction-limited performance 5 (spatial compression) and attosecond phase locking 6–8 (temporal compression) have been demonstrated experimentally, efficient coupling of relativistically intense laser pulse energy into the emitted harmonic cone has not been realized so far. Here we demonstrate that this highly nonlinear interaction can be tailored to deliver the maximum conversion efficiencies predicted from simulations. By fine-tuning the temporal profile of the driving laser on sub-picosecond (<10 −12 s) timescales, energies >9 mJ between the 12th and 47th harmonics are observed. These results are in agreement with the theoretically expected efficiency dependence on harmonic order, verifying that optimal conditions have been achieved in the generation process. This is the important final element required to achieve the expected intensity boosts from a CHF in experiments. Although obtaining spatiotemporal compression and optimal efficiency simultaneously remains challenging, the path to realizing extreme optical field strengths approaching the critical field of quantum electrodynamics (the Schwinger limit at >10 1 6 V cm −1 or >10 29 W cm −2 ) is now open, permitting all-optical studies of the quantum vacuum and new frontiers for intense attosecond science.
Source: Nature
Authors: Robin J. L. Timmis, Colm R. J. Fitzpatrick, Jonathan P. Kennedy, Holly M. Huddleston, Elliott Denis, Abigail James, Chris Baird, Dan Symes, David McGonegle, Eduard Atonga, Heath Martin, Jeremy Rebenstock, John Neely, Jordan Lee, Joshua Redfern, Nicolas Bourgeois, Oliver Finlay, Rusko Ruskov, Sam Astbury, Steve Hawkes, Zixin Zhang, Matt Zepf, Karl Krushelnick, Edward Gumbrell, Paramel Pattathil Rajeev, Mark Yeung, Brendan Dromey, Peter Norreys
Institutions: University of Oxford, John Adams Institute for Accelerator Science, Queen's University Belfast, Rutherford Appleton Laboratory, Central Laser Facility, AWE Nuclear Security Technologies, University of Michigan, Helmholtz Institute Jena, GSI Helmholtz Centre for Heavy Ion Research, Friedrich Schiller University Jena
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $12,690
Awards: Ultrafast laser-driven ion interactions in matter: Evolving dose distribution at the nanoscale and nonlinear response, G4310967859, FOR 2783: Probing the Quantum Vacuum at the HighIntensity Frontier, Plasma Physics HEC Consortia, RELATIVISTIC ELECTRON AND POSITRON BEAMS FROM LASER WAKEFIELD ACCELERATION EXPERIMENTS USING ULTRA-HIGH POWER AND HIGH REP RATE LASERS, Ultrafast Nanodosimetry - the role of the nanoscale in radiation interactions in matter., G8183765751, NSF ZEUS Multi-Petawatt Laser Facility: Operations, Nanorad - Ultrafast, nano-scale material response to radiation and applications of ultrafast radiation sources.
OpenAlex ID: W7155198317