W. M. Fawley

TL;DR: In this paper, a seeded free-electron laser with a two-stage harmonic upshift configuration provided tunable and coherent soft-X-ray pulses with energies of tens of microjoules and a low pulse-to-pulse wavelength jitter at wavelengths of 10.8 nm and below.

TL;DR: The generation of two-colour extreme ultraviolet pulses of controlled wavelengths, intensity and timing by seeding of high-gain harmonic generation free-electron laser with multiple independent laser pulses is reported.

TL;DR: In this article, the authors report the first demonstration of the full output polarization capabilities of FERMI FEL-1 in a campaign of experiments where the wavelength and nominal polarization are set to a series of representative values, and the polarization of the emitted intense pulses is thoroughly characterized by three independent instruments and methods.

TL;DR: In this article, the echo-enabled harmonic generation (EEHG) configuration was used to generate stable, intense, nearly fully coherent pulses at wavelengths as short as 5.9 nm.

TL;DR: In this article, the first instance of FEL wavelength tuning, both in a narrow and in a large spectral range (fine- and coarse-tuning), was reported, and two different experiments were performed exploiting such FEL tuning.