Coherent High-Harmonic Generation with Laser-Plasma Beams

TL;DR

This paper explores a novel active energy compression scheme for laser-plasma accelerators that produces electron beams with extremely low energy spread, enabling coherent high-harmonic generation at unprecedented harmonic orders.

Contribution

It introduces an active energy compression method that achieves ultra-low slice energy spread in laser-plasma accelerator beams, facilitating coherent high-harmonic generation at very high harmonics.

Findings

Achieves small slice energy spread (~10^-5) in laser-plasma beams.

Enables generation of coherent radiation at ~100th harmonic.

Potential for stable, tunable, narrow-band plasma-based radiation.

Abstract

Active energy compression scheme is presently being investigated for future laser-plasma accelerators. This method enables generating laser-plasma accelerator electron beams with a small, $\sim 10^{-5}$, relative slice energy spread. When modulated by a laser pulse, such beams can produce coherent radiation at very high, $\sim 100$-th harmonics of the modulation laser wavelength, which are hard to access by conventional techniques. The scheme has a potential of providing additional capabilities for future plasma-based facilities by generating stable, tunable, narrow-band radiation.