Two-colour generation in a chirped seeded Free-Electron Laser

TL;DR

This paper demonstrates a method for generating two spectrally and temporally separated pulses using a seeded free-electron laser, enabling advanced two-color pump-probe experiments in the extreme-ultraviolet range.

Contribution

It introduces a novel technique for controlling spectral and temporal features of FEL pulses, validated experimentally and through simulations.

Findings

Successful generation of two separated pulses in the EUV range.

Controlled spectral and temporal pulse features demonstrated.

Potential application in jitter-free two-color pump-probe experiments.

Abstract

We present the experimental demonstration of a method for generating two spectrally and temporally separated pulses by an externally seeded, single-pass free-electron laser operating in the extreme-ultraviolet spectral range. Our results, collected on the FERMI@Elettra facility and confirmed by numerical simulations, demonstrate the possibility of controlling both the spectral and temporal features of the generated pulses. A free-electron laser operated in this mode becomes a suitable light source for jitter-free, two-colour pump-probe experiments.