Confocal operation of a transmission electron microscope with two aberration correctors

The authors demonstrate that confocal imaging trajectories can be established in a transmission electron microscope fitted with two spherical aberration correctors. An atomic-scale electron beam, focused by aberration-corrected illumination optics, is directly imaged by a second aberration-corrected system. The initial experiment described indicates how aberration-corrected scanning confocal electron microscopy will allow three-dimensional imaging and analysis of materials with atomic lateral resolution and with a depth resolution of a few nanometers. The depth resolution in the confocal mode is shown to be robust to the uncorrected chromatic aberration of the lenses, unlike depth sectioning using a single lens.