Terahertz-optical intensity grating for creating high-charge, attosecond electron bunches

TL;DR

This paper demonstrates a method to generate high-charge, attosecond electron bunches using terahertz and optical pulses, enabling ultrafast imaging and radiation with existing technology.

Contribution

It introduces a novel approach combining terahertz and optical pulses to produce high-charge, ultrashort electron bunches, surpassing previous limitations.

Findings

Achieved sub-400 attosecond electron bunches with ~1 fC charge.

Produced electron bunches containing >25 electrons within 20 attoseconds.

Validated the feasibility with realistic parameters and current technology.

Abstract

Ultrashort electron bunches are useful for applications like ultrafast imaging and coherent radiation production. Currently, however, the shortest achievable bunches, at attosecond time scales, have only been realized in the single or very few electron regime, limited by Coulomb repulsion and electron energy spread. Using ab initio simulations and theoretical analysis, we show that highly-charged bunches are achievable by subjecting relativistic (few MeV-scale) electrons to a superposition of terahertz and optical pulses. Using realistic electron bunches and laser pulse parameters which are within the reach of current compact setups, we provide two detailed examples: one with final bunches of ~1 fC contained within sub-400 as durations, and one with bunches of >25 electrons contained within 20 as durations. Our results reveal a route to achieve such extreme combinations of high charge and attosecond pulse durations with existing technology.