The time–energy information of ultrashort X-ray free-electron laser pulses generated by the Linac Coherent Light Source is measured with attosecond resolution via angular streaking of neon 1s photoelectrons. The X-ray pulses promote electrons from the neon core level into an ionization continuum, where they are dressed with the electric field of a circularly polarized infrared laser. This induces characteristic modulations of the resulting photoelectron energy and angular distribution. From these modulations we recover the single-shot attosecond intensity structure and chirp of arbitrary X-ray pulses based on self-amplified spontaneous emission, which have eluded direct measurement so far. We characterize individual attosecond pulses, including their instantaneous frequency, and identify double pulses with well-defined delays and spectral properties, thus paving the way for X-ray pump/X-ray probe attosecond free-electron laser science.
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Hentschel, M. et al. Attosecond metrology. Nature 414, 509–513 (2001).
Krausz, F. & Stockman, M. I. Attosecond metrology: from electron capture to future signal processing. Nat. Photon. 8, 205–213 (2014).
Drescher, M. X-ray pulses approaching the attosecond frontier. Science 291, 1923–1927 (2001).
Eckle, P. et al. Attosecond ionization and tunneling delay time measurements in helium. Science 322, 1525–1529 (2008).
Schultze, M. et al. Delay in photoemission. Science 328, 1658–1662 (2010).
Cavalieri, A. L. et al. Attosecond spectroscopy in condensed matter. Nature 449, 1029–1032 (2007).
Neppl, S. et al. Direct observation of electron propagation and dielectric screening on the atomic length scale. Nature 517, 342–346 (2015).
Goulielmakis, E. et al. Real-time observation of valence electron motion. Nature 466, 739–743 (2010).
Kraus, P. M. et al. Measurement and laser control of attosecond charge migration in ionized iodoacetylene. Science 350, 790–795 (2015).
Baker, S. et al. Probing proton dynamics in molecules on an attosecond time scale. Science 312, 424–427 (2006).
Schultze, M. et al. Controlling dielectrics with the electric field of light. Nature 493, 75–78 (2014).
Emma, P. et al. First lasing and operation of an ångstrom-wavelength free-electron laser.Nat. Photon. 4, 641–647 (2010).
Ishikawa, T. et al. A compact X-ray free-electron laser emitting in the sub-ångström region. Nat. Photon. 6, 540–544 (2012).
Allaria, E. et al. Two-stage seeded soft-X-ray free-electron laser. Nat. Photon. 7, 913–918 (2013).
Kang, H. -S. et al. Hard X-ray free-electron laser with femtosecond-scale timing jitter. Nat. Photon. 11, 708–713 (2017).
Altarelli, M. The European X-ray free-electron laser facility in Hamburg. Nucl. Instrum. Methods Phys. Res. Sect. B 269, 2845–2849 (2011).
Milne, C. et al. SwissFEL: The Swiss X-ray Free Electron Laser. Appl. Sci. 7, 720 (2017).
Young, L. et al. Femtosecond electronic response of atoms to ultra-intense X-rays. Nature 466, 56–61 (2010).
Zhang, W. et al. Tracking excited-state charge and spin dynamics in iron coordination complexes. Nature 509, 345–348 (2014).
Seibert, M. M. et al. Single mimivirus particles intercepted and imaged with an X-ray laser. Nature 470, 78–81 (2011).
Milathianaki, D. et al. Femtosecond visualization of lattice dynamics in shock-compressed matter. Science 342, 220–223 (2013).
Prince, K. C. et al. Coherent control with a short-wavelength free-electron laser. Nat. Photon. 10, 176–179 (2016).
Milton, S. V. et al. Exponential gain and saturation of a self-amplified spontaneous emission free-electron laser. Science 292, 2037–2041 (2001).
Li, J. et al. 53-attosecond X-ray pulses reach the carbon K-edge. Nat. Commun. 8, 186 (2017).
Lutman, A. et al. Femtosecond X-ray free electron laser pulse duration measurement from spectral correlation function. Phys. Rev. ST Accel. Beams 15, 030705 (2012).
Inubushi, Y. et al. Determination of the pulse duration of an X-ray free electron laser using highly resolved single-shot spectra. Phys. Rev. Lett. 109, 144801 (2012).
Ding, Y. et al. Femtosecond X-ray pulse characterization in free-electron lasers using a cross-correlation technique. Phys. Rev. Lett. 109, 254802 (2012).
Behrens, C. et al. Few-femtosecond time-resolved measurements of X-ray free-electron lasers. Nat. Commun. 5, 3762 (2014).
Sanchez-Gonzalez, A. et al. Accurate prediction of X-ray pulse properties from a free-electron laser using machine learning. Nat. Commun. 8, 15461 (2017).
Krinsky, S. & Gluckstern, R. Analysis of statistical correlations and intensity spiking in the self-amplified spontaneous-emission free-electron laser. Phys. Rev. ST Accel. Beams 6, 050701 (2003).
Zholents, A. & Fawley, W. Proposal for intense attosecond radiation from an X-ray free-electron laser. Phys. Rev. Lett. 92, 224801 (2004).
Kumar, S., Kang, H.-S. & Kim, D. E. Tailoring the amplification of attosecond pulse through detuned X-ray FEL undulator. Opt. Express 23, 2808–2818 (2015).
Prat, E. & Reiche, S. Simple method to generate terawatt-attosecond X-ray free-electron-laser pulses. Phys. Rev. Lett. 114, 244801 (2015).
Marinelli, A. et al. Optical shaping of X-ray free-electron lasers. Phys. Rev. Lett. 116, 254801 (2016).
Lutman, A. A. et al. Fresh-slice multicolour X-ray free-electron lasers. Nat. Photon 10, 745–750 (2016).
Huang, S. et al. Generating single-spike hard X-ray pulses with nonlinear bunch compression in free-electron lasers. Phys. Rev. Lett. 119, 154801 (2017).
Helml, W. et al. Measuring the temporal structure of few-femtosecond free-electron laser X-ray pulses directly in the time domain. Nat. Photon. 8, 950–957 (2014).
Düsterer, S. et al. Femtosecond x-ray pulse length characterization at the Linac Coherent Light Source free-electron laser. New J. Phys. 13, 093024 (2011).
Grguraš, I. et al. Ultrafast X-ray pulse characterization at free-electron lasers. Nat. Photon 6, 852–857 (2012).
Hartmann, N. et al. Sub-femtosecond precision measurement of relative X-ray arrival time for free-electron lasers. Nat. Photon. 8, 706–709 (2014).
Bionta, M. R. et al. Spectral encoding method for measuring the relative arrival time between X-ray/optical pulses. Rev. Sci. Instrum 85, 083116 (2014).
Kazansky, A. K., Bozhevolnov, A. V., Sazhina, I. P. & Kabachnik, N. M. Interference effects in angular streaking with a rotating terahertz field. Phys. Rev. A 93, 013407 (2016).
Kazansky, A. K., Sazhina, I. P., Nosik, V. L. & Kabachnik, N. M. Angular streaking and sideband formation in rotating terahertz and far-infrared fields. J. Phys. B 50, 105601 (2017).
Allaria, E. et al. Control of the polarization of a vacuum-ultraviolet, high-gain, free-electron laser. Phys. Rev. X 4, 041040 (2014).
Lutman, A. A. et al. Polarization control in an X-ray free-electron laser. Nat. Photon. 10, 468–472 (2016).
Gagnon, J. & Yakovlev, V. S. The direct evaluation of attosecond chirp from a streaking measurement. Appl. Phys. B 103, 303–309 (2011).
Constant, E., Taranukhin, V., Stolow, A. & Corkum, P. Methods for the measurement of the duration of high-harmonic pulses. Phys. Rev. A 56, 3870–3878 (1997).
Eckle, P. et al. Attosecond angular streaking. Nat. Phys. 4, 565–570 (2008).
Itatani, J. et al. Attosecond streak camera. Phys. Rev. Lett. 88, 173903 (2002).
Kienberger, R. et al. Atomic transient recorder. Nature 427, 817–821 (2004).
Kazansky, A. K., Sazhina, I. P. & Kabachnik, N. M. Angle-resolved electron spectra in short-pulse two-color XUV+IR photoionization of atoms. Phys. Rev. A 82, 033420 (2010).
Behrens, C. et al. Constraints on photon pulse duration from longitudinal electron beam diagnostics at a soft x-ray free-electron laser. Phys. Rev. ST Accel. Beams 15, 030707 (2012).
Pellegrini, C., Marinelli, A. & Reiche, S. The physics of x-ray free-electron lasers. Rev. Mod. Phys. 88, 015006 (2016).
Li, Y., Lewellen, J., Huang, Z., Sajaev, V. & Milton, S. V. Time-resolved phase measurement of a self-amplified free-electron laser. Phys. Rev. Lett. 89, 234801 (2002).
Emma, P. et al. Femtosecond and Subfemtosecond X-Ray Pulses from a SASE Based Free-Electron Laser. Phys. Rev. Lett. 92, 074801 (2004).
Helml, W. et al. Ultrashort free-electron laser X-ray pulses. Appl. Sci. 7, 915–956 (2017).
We would like to thank C. Bostedt for his extensive and skilful support during the beam time. This research was carried out at the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory. LCLS is an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Stanford University. W.H. acknowledges financial support from a Marie Curie International Outgoing Fellowship. W.H., R.H., M.S.W. and R.K. acknowledge financial support by the BaCaTeC program, the German Cluster of Excellence MAP and the European I3-Initiative 'LASERLAB-Europe IV'. R.K. acknowledges an ERC Consolidator Grant 'AEDMOS'. J.K., A.A.L, A.M., T.M., S.M., R.N.C. and J.R. acknowledge DOE support under contract DE-AC02-76SF00515. N.M.K. acknowledges financial support from the theory group in cooperation with the SQS work package of European XFEL. A.K.K. acknowledges financial support from the project FIS2016-76617-P of MINECO. T.F. acknowledges financial support from the National Center of Competence in Research, Molecular Ultrafast Science and Technology. M.I. acknowledges funding of the Volkswagen Foundation within a Peter Paul Ewald-Fellowship.
The authors declare no competing interests.
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Hartmann, N., Hartmann, G., Heider, R. et al. Attosecond time–energy structure of X-ray free-electron laser pulses. Nature Photon 12, 215–220 (2018). https://doi.org/10.1038/s41566-018-0107-6
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