title: Experimental demonstration of enhanced self-amplified spontaneous emission by an optical klystron.
abstract: We report the first experimental evidence of enhancement of self-amplified spontaneous emission, due to the use of an optical klystron. In this free-electron laser scheme, a relativistic electron beam passes through two undulators, separated by a dispersive section. The latter converts the electron-beam energy modulation produced in the first undulator in density modulation, thus enhancing the free-electron laser gain. The experiment has been carried out at the FERMI facility in Trieste. Powerful radiation has been produced in the extreme ultraviolet range, with an intensity a few orders of magnitude larger than in pure self-amplified spontaneous emission mode. Data have been benchmarked with an existing theoretical model.
authors.affiliation: Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale 14 - km 163.5 in AREA Science Park, 34149 Basovizza, Trieste, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Penco
authors.affiliation: Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale 14 - km 163.5 in AREA Science Park, 34149 Basovizza, Trieste, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Allaria
authors.affiliation: Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale 14 - km 163.5 in AREA Science Park, 34149 Basovizza, Trieste, Italy and Laboratory of Quantum Optics, University of Nova Gorica, 5001 Nova Gorica, Slovenia.
authors.forename: G
authors.initials: G
authors.lastname: De Ninno
authors.affiliation: Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale 14 - km 163.5 in AREA Science Park, 34149 Basovizza, Trieste, Italy and Università degli Studi di Trieste, Dipartimento di Fisica, Piazzale Europa 1, 34100 Trieste, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Ferrari
authors.affiliation: Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale 14 - km 163.5 in AREA Science Park, 34149 Basovizza, Trieste, Italy and Enea, via Enrico Fermi 45, 00044 Frascati, Roma, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Giannessi