Highoral-resolution electron microscopy for imaging ultrafast electron dynamics

Ultrafast electron microscopy (UEM) has been demonstrated as an effective table-top technique for imaging the temporally evolving dynamics of matter with a subparticle spatial resolution on the timescale of atomic motion. However, imaging the faster motion of electron dynamics in real time has remained beyond reach. Here we demonstrate more than an order of magnitude (16 times) enhancement in the typical temporal resolution of UEM by generating isolated 30 fs electron pulses, accelerated at 200 keV, via the optical-gating approach, with sufficient intensity to probe efficiently the electronic dynamics of matter. Moreover, we investigate the feasibility of attosecond optical gating to generate isolated subfemtosecond electron pulses and attain the desired temporal resolution in electron microscopy to establish attomicroscopy to allow the imaging of electron motion in the act.