@article{e0c56621ea3547b7826c343ec951b704,
title = "Determining the polarization state of an extreme ultraviolet free-electron laser beam using atomic circular dichroism",
abstract = "Ultrafast extreme ultraviolet and X-ray free-electron lasers are set to revolutionize many domains such as bio-photonics and materials science, in a manner similar to optical lasers over the past two decades. Although their number will grow steadily over the coming decade, their complete characterization remains an elusive goal. This represents a significant barrier to their wider adoption and hence to the full realization of their potential in modern photon sciences. Although a great deal of progress has been made on temporal characterization and wavefront measurements at ultrahigh extreme ultraviolet and X-ray intensities, only few, if any progress on accurately measuring other key parameters such as the state of polarization has emerged. Here we show that by combining ultra-short extreme ultraviolet free electron laser pulses from FERMI with near-infrared laser pulses, we can accurately measure the polarization state of a free electron laser beam in an elegant, non-invasive and straightforward manner using circular dichroism.",
author = "T. Mazza and M. Ilchen and Rafipoor, {A. J.} and C. Callegari and P. Finetti and O. Plekan and Prince, {K. C.} and R. Richter and Danailov, {M. B.} and A. Demidovich and {De Ninno}, G. and C. Grazioli and R. Ivanov and N. Mahne and L. Raimondi and C. Svetina and L. Avaldi and P. Bolognesi and M. Coreno and P. O'Keeffe and {Di Fraia}, M. and M. Devetta and Y. Ovcharenko and Th M{\"o}ller and V. Lyamayev and F. Stienkemeier and S. D{\"u}sterer and K. Ueda and Costello, {J. T.} and Kazansky, {A. K.} and Kabachnik, {N. M.} and M. Meyer",
note = "Funding Information: The authors thank the many members of the FERMI Team at Elettra-Sincrotrone Trieste who contributed to this project, including the accelerator operations group, the information technology group and all engineering support teams. The LDM@FERMI beamline acknowledges support by the Regione Autonoma Friuli Venezia Giulia Project ANGEL, POR-FESR 2007-2013-Regional Competitiveness and Employment Objective-Activity (1.1.a)2, and by the Italian–Slovenian Crossborder Cooperation Programme (CITIUS project, 2013/2010090600115298). M.I. acknowledges funding from the Volkswagen Foundation, and M.I. and A.J.R. received financial support from SFB 925 {\textquoteleft}Light induced dynamics and control of correlated quantum systems{\textquoteright} at the University of Hamburg. T.M. and M.M. acknowledge financial support by Elettra within the CALIPSO Transnational Access Programme. The participation of J.T.C. is supported under SFI grant No. 12/IA/1742. N.M.K. acknowledges financial support from the programme {\textquoteleft}Physics with Accelerators and Reactors in West Europe{\textquoteright} of the Russian Ministry of Education and Science.",
year = "2014",
month = apr,
day = "16",
doi = "10.1038/ncomms4648",
language = "English",
volume = "5",
journal = "Nature Communications",
issn = "2041-1723",
publisher = "Nature Publishing Group",
}