Publication date: 17th July 2025
Time-resolved variants of transmission electron microscopy have started to provide an unparalleled view into the fast and ultrafast dynamics of solid-state nanostructures. A crucial instrumental pre-requisite for constructing the next generation of time-resolved electron microscopes is the development of novel pulsed electron sources, fast detectors and versatile sample excitation schemes. In the first part of the talk, our recent development of a novel laser-driven cold-field emitter source is described [1]. The properties of extracted photoelectron pulses, including the achieved electron pulse duration, spectral width, and electron beam brightness, are characterized in detail, and the advantages of aberration-corretected ultrafast transmission electron microscopy are discussed.
The second part focusses on the application of event-based TimePix3 electron detectors for the time-resolved probing of nonlinear structural dynamics in nanoscale resonatorss. We demonstrate the phase-resolved mapping of nonlinear Duffing modes in a silicon membrane resonator with quality factors exceeding 105. Higher harmonics of the driving frequency are observed in the structural response, indicatig the emergencs of multi-mode coupling channels with large effective nonlinearities. At the largest driving strengths, periode doubling bifurcations emerge highlighting the onset of temporal symmetry breaking in a simple repetitively driven nanoscale system.