Particle accelerators driven by laser-generated terahertz (THz) pulses promise unprecedented control over the energy–time phase space of particle bunches compared with conventional radiofrequency technology. Here we demonstrate acceleration of a relativistic electron beam in a THz-driven linear accelerator. Narrowband THz pulses were tuned to the phase-velocity-matched operating frequency of a rectangular dielectric-lined waveguide for extended collinear interaction with 35 MeV, 60 pC electron bunches, imparting multicycle energy modulation to chirped (6 ps) bunches and injection phase-dependent energy gain (up to 10 keV) to subcycle (2 ps) bunches. These proof-of-principle results establish a route to whole-bunch linear acceleration of subpicosecond particle beams, directly applicable to scaled-up and multistaged concepts capable of preserving beam quality, thus marking a key milestone for future THz-driven acceleration of relativistic beams.

与传统的射频技术相比，由激光产生的太赫兹（THz）脉冲驱动的粒子加速器有望对粒子束的能量-时间相空间进行前所未有的控制。在这里，我们演示了在太赫兹驱动的线性加速器中相对论电子束的加速。将窄带THz脉冲调谐到矩形介质衬里波导的相速度匹配工作频率，以与35 MeV，60 pC电子束扩展共线相互作用，对chi束（6 ps）进行多周期能量调制，并取决于注入相位能量增益（高达10 keV）子周期（2 ps）。这些原理证明的结果为亚皮秒粒子束的全束线性加速建立了一条途径，