Lasing of a cavity-based X-ray source.

ABSTRACT: The invention of the laser transformed optics by providing intense, coherent light in the visible region, but extending this concept to X-rays has been hindered by a lack of suitable gain media and mirrors. Current hard X-ray free-electron laser (XFEL) facilities^1-5 overcome this by amplifying shot noise from a high-peak-current electron bunch via self-amplified spontaneous emission⁶ in a single pass through long undulators, delivering very high brightness but with a noisy, multi-spiked temporal and spectral profile. Cavity-based XFELs (CBXFELs)^7-9 were proposed to close this gap by recirculating spectrally filtered X-ray pulses in a Bragg-reflecting cavity synchronized to a high-repetition-rate electron beam. Here we show lasing with multi-pass gain at 6.9

SUBMITTER: Rauer P 

PROVIDER: S-EPMC12872447 | biostudies-literature | 2026 Feb

REPOSITORIES: biostudies-literature