An all-optical electron gun.

Abstract

Optics Short bunches of electrons are used extensively to yield information about the structure of materials and the dynamics of phase transitions. Traditionally associated, perhaps, with “big science,” the availability of accelerator beam time and the timing resolution of the pulses can be limiting factors for experimental studies. Huang et al. have developed a matchbox-sized all-optical electron gun in which a single terahertz pulse is injected into a copper waveguide. Synchronized with a photogenerated pulse of electrons, the terahertz pulse accelerates the electron bunch over high fields and with low energy spread so that they can be used for low-energy electron diffraction studies. Further developments could lead to the generation of ultrashort relativistic electron bunches and the prospect of miniaturized accelerators. Optica 3 , 1209 (2016).