Ultrafast Transmission Electron Microscopy with an Optically Modulated Beam

Abstract

Electron microscopes equipped with pulsed electron guns can capture phenomena faster than the shutter speed of a camera. However, the temporal resolution is sub-picoseconds, which is often insufficient to capture the very fast motion of atoms and electrons. Recently, a novel technique, namely, the optical modulation of electron beams, has been developed in order to achieve attosecond temporal resolution, and has attracted much attention. In this paper, we review the background of the transmission electron microscopy using optically-modulated electron beams, the principle of the optical modulation, and the applications that have been reported so far. Electron microscopy with attosecond resolution should become a powerful tool for visualizing the microscopic motion of electrons and electromagnetic fields of light in and around nanomaterials, which has been difficult to achieve so far.