Terahertz-based attosecond metrology of relativistic electron beams

TL;DR

This paper demonstrates attosecond-level control and measurement of relativistic electron beams using phase-locked terahertz radiation, enabling unprecedented precision in electron beam manipulation for ultrafast science.

Contribution

It introduces a novel method for attosecond electron metrology using laser-generated terahertz radiation phase-locked to optical pulses.

Findings

Achieved control of relativistic electron beams at attosecond timescales

Demonstrated single-shot characterization of bright electron beams

Enabled new possibilities for atomic visualization

Abstract

Photons, electrons, and their interplay are at the heart of photonic devices and modern instruments for ultrafast science [1-10]. Nowadays, electron beams of the highest intensity and brightness are created by photoemission with short laser pulses, and then accelerated and manipulated using GHz radiofrequency electromagnetic fields. The electron beams are utilized to directly map photoinduced dynamics with ultrafast electron scattering techniques, or further engaged for coherent radiation production at up to hard X-ray wavelengths [11-13]. The push towards improved timing precision between the electron beams and pump optical pulses though, has been stalled at the few tens of femtosecond level, due to technical challenges with synchronizing the high power rf fields with optical sources. Here, we demonstrate attosecond electron metrology using laser-generated single-cycle THz radiation, which is intrinsically phase locked to the optical drive pulses, to manipulate multi-MeV relativistic electron beams. Control and single-shot characterization of bright electron beams at this unprecedented level open up many new opportunities for atomic visualization.