‘Einstein’s flying mirror’ inspires scientists to build powerful light beams

Researchers at the University of Oxford and Queen’s University Belfast used ultrashort laser pulses on a glass target to create a plasma mirror and concentrate reflected light into a nanometer-scale focus.

The setup produced exceptionally intense XUV and X-ray beams, with theoretical peak intensities around 10^23 W/cm² and a route toward even stronger fields.

The work, reported in Nature and enabled by the Gemini Laser and Central Laser Facility, advances relativistic harmonic generation and coherent harmonic focus techniques.

It could help test quantum electrodynamics and vacuum effects near the Schwinger limit, while also supporting ultrafast imaging, photolithography, and fusion research.