Control of the polarization of a vacuum-ultraviolet, high-gain, free-electron laser

Enrico Allaria, Bruno Diviacco, Carlo Callegari, Paola Finetti, Beno�t Mahieu, Jens Viefhaus, Marco Zangrando, Giovanni De Ninno, Guillaume Lambert, Eugenio Ferrari, Jens Buck, Markus Ilchen, Boris Vodungbo, Nicola Mahne, Cristian Svetina, Carlo Spezzani, Simone Di Mitri, Giuseppe Penco, Mauro Trov�, William M. FawleyPrimoz R. Rebernik, David Gauthier, Cesare Grazioli, Marcello Coreno, Barbara Ressel, Antti Kivim�ki, Tommaso Mazza, Leif Glaser, Frank Scholz, Joern Seltmann, Patrick Gessler, Jan Gr�nert, Alberto De Fanis, Michael Meyer, Andr� Knie, Stefan P. Moeller, Lorenzo Raimondi, Flavio Capotondi, Emanuele Pedersoli, Oksana Plekan, Miltcho B. Danailov, Alexander Demidovich, Ivaylo Nikolov, Alessandro Abrami, Julien Gautier, Jan L�ning, Philippe Zeitoun, Luca Giannessi

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90 Citations (Scopus)


The two single-pass, externally seeded free-electron lasers (FELs) of the FERMI user facility are designed around Apple-II-type undulators that can operate at arbitrary polarization in the vacuum ultraviolet-to-soft x-ray spectral range. Furthermore, within each FEL tuning range, any output wavelength and polarization can be set in less than a minute of routine operations. We 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, expressly developed for the task. The measured radiation polarization is consistently > 90% and is not significantly spoiled by the transport optics; differing, relative transport losses for horizontal and vertical polarization become more prominent at longer wavelengths and lead to a non-negligible ellipticity for an originally circularly polarized state. The results from the different polarimeter setups validate each other, allow a cross-calibration of the instruments, and constitute a benchmark for user experiments.
Original languageEnglish
Article number041040
Pages (from-to)-
JournalPhysical Review X
Issue number4
Publication statusPublished - 2014
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Cite this

Allaria, E., Diviacco, B., Callegari, C., Finetti, P., Mahieu, B., Viefhaus, J., Zangrando, M., De Ninno, G., Lambert, G., Ferrari, E., Buck, J., Ilchen, M., Vodungbo, B., Mahne, N., Svetina, C., Spezzani, C., Di Mitri, S., Penco, G., Trov�, M., ... Giannessi, L. (2014). Control of the polarization of a vacuum-ultraviolet, high-gain, free-electron laser. Physical Review X, 4(4), -. [041040].