Light-based electron aberration corrector.

Achieving atomic resolution in electron microscopy has historically been hindered by spherical aberration, a fundamental limitation of conventional electron lenses. Its correction typically requires complex assemblies of electromagnetic multipoles. Here we demonstrate that third-order spherical aberration in a cylindrically symmetric electron lens with an associated aberration coefficient of C s ≈ 2.5 m can be compensated to near-zero via interaction with a shaped light field. By analysing distortions in the high-magnification point-projection electron images of optical standing waves, we quantify the spherical aberration before and after light-induced correction. The spatial distribution of the correction optical field is precisely characterized in situ using ultrafast four-dimensional scanning transmission electron microscopy utilizing the transverse deflection of electrons induced by the optical ponderomotive force. Such a combined characterization and correction approach introduces a new paradigm for optical control in electron beams and opens a pathway towards compact and tunable light-based correctors for high-resolution electron microscopy.