Ultrafast Transmission Electron Microscopy: Historical Development, Instrumentation, and Applications

International audienceTransmission Electron Microscopes (TEM) have allowed giant steps in chemistry, biology or physics. Many of these achievements were nourished by key instrumental developments such as aberration correctors, high brightness sources, detectors, etc. Despite spectacular advances, investigations using TEM have long been restricted to systems either static or evolving on timescales compatible with the frame rate of CCD cameras. Time-resolved Transmission Electron Microscopy aims at overcoming this limitation and exploring the dynamics of nanoscale systems. Since the pioneering work of the group of O. Bostanjoglo at the TU Berlin, spectacular progress has been made to provide time-resolved TEM with a constantly improving spatio-temporal resolution. These advances rely mostly, although not exclusively, on ultrafast lasers and are largely inspired from time-resolved optical spectroscopy techniques.In this review, we provide an introduction to the field of time-resolved TEM, describe the major instrumental developments, and give examples of applications in different fields. In Section 5, we discuss the possibility of performing time-resolved electron holography with new high brightness UTEMs