title: Multi-colour pulses from seeded free-electron-lasers: towards the development of non-linear core-level coherent spectroscopies.
abstract: We report on new opportunities for ultrafast science thanks to the use of two-colour extreme ultraviolet (XUV) pulses at the FERMI free electron laser (FEL) facility. The two pulses have been employed to carry out a pioneering FEL-pump/FEL-probe diffraction experiment using a Ti target and tuning the FEL pulses to the M(2/3)-edge in order to explore the dependence of the dielectric constant on the excitation fluence. The future impact that the use of such a two-colour FEL emission will have on the development of ultrafast wave-mixing methods in the XUV/soft X-ray range is addressed and discussed.
authors.affiliation: Elettra-Sincrotrone Trieste S.C.p.A., S.S. 14 km 163,5 in AREA Science Park, I-34149, Basovizza, Trieste, Italy. filippo.bencivenga@elettra.eu claudio.masciovecchio@elettra.eu.
authors.forename: Filippo
authors.initials: F
authors.lastname: Bencivenga
authors.forename: Flavio
authors.initials: F
authors.lastname: Capotondi
authors.forename: Francesco
authors.initials: F
authors.lastname: Casolari
authors.forename: Francesco
authors.initials: F
authors.lastname: Dallari
authors.forename: Miltcho B
authors.initials: MB
authors.lastname: Danailov
authors.forename: Giovanni
authors.initials: G
authors.lastname: De Ninno
authors.forename: Daniele
authors.initials: D
authors.lastname: Fausti
authors.forename: Maya
authors.initials: M
authors.lastname: Kiskinova
authors.forename: Michele
authors.initials: M
authors.lastname: Manfredda
authors.forename: Claudio
authors.initials: C
authors.lastname: Masciovecchio
authors.forename: Emanuele
authors.initials: E
authors.lastname: Pedersoli
mesh_terms: D004583:Electrons; D007834:Lasers; D013057:Spectrum Analysis; D014965:X-Rays