Free-electron radiation engineering via structured environments

TL;DR

This paper reviews recent theoretical and experimental advances in controlling free-electron radiation using structured environments like 2D materials and photonic crystals, highlighting new opportunities in various technological fields.

Contribution

It offers a comprehensive overview of recent developments in free-electron radiation control through structured environments, including both spontaneous and stimulated phenomena.

Findings

Advances in controlling spontaneous free-electron radiation in structured media.

Observation of stimulated free-electron radiation involving photonic quasi-particles.

Identification of future research directions in free-electron radiation engineering.

Abstract

Free-electron radiation results from the interaction between swift electrons and the local electromagnetic environment. Recent advances in material technologies provide powerful tools to control light emission from free electrons and may facilitate many intriguing applications of free-electron radiation in particle detections, lasers, quantum information processing, etc. Here, we provide a brief overview on the recent theoretical developments and experimental observations of spontaneous free-electron radiation in various structured environments, including two-dimensional materials, metasurfaces, metamaterials, and photonic crystals. We also report on research progresses on the stimulated free-electron radiation that results from the interaction between free electrons and photonic quasi-particles induced by the external field. Moreover, we provide an outlook of potential research directions for this vigorous realm of free-electron radiation.