title: Coherent light with tunable polarization from single-pass free-electron lasers.
abstract: Tunable polarization over a wide spectral range is a required feature of light sources employed to investigate the properties of local symmetry in matter. In this Letter, we provide the first experimental characterization of the polarization of the harmonic light produced by a free-electron laser and demonstrate a method to obtain free-electron laser harmonics with tunable polarization. Experimental results are successfully compared with theory. Our findings can be expected to have a deep impact on the design and realization of experiments requiring full control of light polarization.
authors.affiliation: Sincrotrone Trieste, S.S. 14 km 163.5, Basovizza (Trieste), Italy.
authors.forename: C
authors.initials: C
authors.lastname: Spezzani
authors.forename: E
authors.initials: E
authors.lastname: Allaria
authors.forename: M
authors.initials: M
authors.lastname: Coreno
authors.forename: B
authors.initials: B
authors.lastname: Diviacco
authors.forename: E
authors.initials: E
authors.lastname: Ferrari
authors.forename: G
authors.initials: G
authors.lastname: Geloni
authors.forename: E
authors.initials: E
authors.lastname: Karantzoulis
authors.forename: B
authors.initials: B
authors.lastname: Mahieu
authors.forename: M
authors.initials: M
authors.lastname: Vento
authors.forename: G
authors.initials: G
authors.lastname: De Ninno