We can now make high-power laser light using a beam of electrons in a device that fits on a tabletop.
April 17, 2026
Original Paper
Optical superradiance from single-digit-femtosecond electron beam structure
arXiv · 2604.13372
The Takeaway
To get coherent light from electrons, you usually need massive particle accelerators that are hundreds of feet long. Researchers just observed this same effect—optical superradiance—from tiny electron bunches that are only a few quadrillionths of a second long. This means we can generate intense, laser-like light in a much smaller, cheaper package. It is like taking the power of a giant industrial lighthouse and shrinking it down to a flashlight. This could revolutionize everything from medical scanning to the manufacturing of microchips.
From the abstract
We report measurements of superradiant optical transition radiation in the 550-800 nm range produced by ultrashort relativistic electron bunches at a dielectric boundary. In the measured optical spectra, we observe photon production with quadratic charge dependence in the visible range, consistent with optical frequency coherence determined by the longitudinal electron bunch form factor. The measured spectral envelope is reproduced by a theoretical model of coherent transition radiation (CTR), w