2026-10-07T20:01:27Z https://www.scidb.cn/oai

10.57760/sciencedb.38715 2026-06-08T09:06:55Z

2026-06-08 All-optical longitudinal fine structure reconstruction for pre-bunched electron beams doi:10.57760/sciencedb.38715 en Since the advent of laser-plasma acceleration (LPA), relativistic microbunching electron beams generated from all-optical systems have become feasible and will enable advanced applications such as X-ray free-electron lasers and ultrafast electron diffraction. This paper proposes an all-optical scheme for generating attosecond-scale pre-bunched electron beams integrated with attosecond-resolution diagnostics. An electron beam from an LPA (523.8 MeV, 1\% energy spread) is simultaneously injected with a 266 nm laser into a modulator to induce energy modulation, which is subsequently converted into density modulation through a dispersive section. A microbunching beam with full width at half maximum (FWHM) of 41.5 nm (138 as) sub-structures and a peak current of 20 kA is achieved and then focused onto an aluminum foil to generate coherent transition radiation (CTR) signals. With a temporal retrieval algorithm, a longitudinal diagnostic resolution of 68 nm (227 as) is successfully demonstrated. Further analysis reveals that the resolution of CTR diagnostic is fundamentally limited by the plasma frequency of metallic materials (15.3 eV for aluminum, cutoff wavelength at 67 nm), making it difficult to reach the sub-attosecond regime. As an alternative, coherent synchrotron radiation (CSR) can circumvent material-dependent limitations and offer higher resolution, but its chromatic dispersion inevitably distorts the attosecond microstructure. This all-optical framework opens a new pathway toward compact ultrafast electron beam sources and other advanced applications. Laser Plasma Acceleration; Microbunching Electron Beams; Fine Structure Reconstruction 郭子笑 Ke Feng Guiao Wang Zhiheng Lou Wentao Wang Ruxin Li RESTRICTED dataset Science Data Bank