Stable ultrafast graphene hot-electron source on optical fiber

作者：Guangjie Yao, Hao Hong, Xu Zhou, Kaifeng Lin, Huazhan Liu, Yilong You, Chang Liu, Ke Chen, Chi Li, Jianbo Yin, Zhu‐Jun Wang, Xuewen Fu, Qing Dai, Dapeng Yu, Kaihui Liu · 发表于：Nature Communications · 年份：2025 · DOI：10.1038/s41467-025-60915-x · 被引用次数：6 · 研究领域：Nanowire Synthesis and Applications、Advanced Electron Microscopy Techniques and Applications、Graphene research and applications

A stable and durable ultrafast electron source is highly desirable for sophisticated vacuum electron technologies. However, free-space excitations based on ultrahigh-power or deep-ultraviolet pulsed lasers usually cause cathode material damage and mechanical vibration even under ultrahigh vacuum. In this work, we present a compact ultrafast electron source consisting of graphene integrated on an optical fiber, taking advantage of the ultrafast hot-electron emission from graphene and well-defined single-mode excitation from the optical fiber. With mild excitation (~1 GW/cm2, infrared laser), an ultrashort electron pulse (width of ~ 80 fs) with high stability (fluctuation ≤±0.5% in 8 hours) and longevity (T90 > 500 hours) can be generated even under relatively high ambient pressure (up to 100 Pa). This compact source has been facilely integrated into a commercial electron microscope for time-resolved imaging and spectroscopy. Our graphene optical fiber-based ultrafast electron source offers a promising solution to support the development of vacuum electron instruments. Ultrafast electron sources are essential for time-resolved electron microscopy techniques, but they usually suffer from limited stability and short lifetimes. Here, the authors report the fabrication of ultrafast hot-electron sources consisting of graphene films integrated on a single-mode optical fibre, showing enhanced stability and longevity.