Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Diffraction and microscopy with attosecond electron pulse trains


Attosecond spectroscopy1,2,3,4,5,6,7 can resolve electronic processes directly in time, but a movie-like space–time recording is impeded by the too long wavelength (~100 times larger than atomic distances) or the source–sample entanglement in re-collision techniques8,9,10,11. Here we advance attosecond metrology to picometre wavelength and sub-atomic resolution by using free-space electrons instead of higher-harmonic photons1,2,3,4,5,6,7 or re-colliding wavepackets8,9,10,11. A beam of 70-keV electrons at 4.5-pm de Broglie wavelength is modulated by the electric field of laser cycles into a sequence of electron pulses with sub-optical-cycle duration. Time-resolved diffraction from crystalline silicon reveals a < 10-as delay of Bragg emission and demonstrates the possibility of analytic attosecond–ångström diffraction. Real-space electron microscopy visualizes with sub-light-cycle resolution how an optical wave propagates in space and time. This unification of attosecond science with electron microscopy and diffraction enables space–time imaging of light-driven processes in the entire range of sample morphologies that electron microscopy can access.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Concept and experiment.
Fig. 2: Attosecond electron pulses.
Fig. 3: Atomic diffraction with attosecond electron pulses.
Fig. 4: Attosecond electron microscopy of electromagnetic waveform propagation.


  1. 1.

    Paul, P. M. et al. Observation of a train of attosecond pulses from high harmonic generation. Science 292, 1689–1692 (2001).

    ADS  Article  Google Scholar 

  2. 2.

    Hentschel, M. et al. Attosecond metrology. Nature 414, 509–513 (2001).

    ADS  Article  Google Scholar 

  3. 3.

    Kienberger, R. et al. Atomic transient recorder. Nature 427, 817–821 (2004).

    ADS  Article  Google Scholar 

  4. 4.

    Smirnova, O. et al. High harmonic interferometry of multi-electron dynamics in molecules. Nature 460, 972–977 (2009).

    ADS  Article  Google Scholar 

  5. 5.

    Sansone, G. et al. Electron localization following attosecond molecular photoionization. Nature 465, 763–766 (2010).

    ADS  Article  Google Scholar 

  6. 6.

    Lucchini, M. et al. Attosecond dynamical Franz-Keldysh effect in polycrystalline diamond. Science 353, 916–919 (2016).

    ADS  Article  Google Scholar 

  7. 7.

    Tao, Z. S. et al. Direct time-domain observation of attosecond final-state lifetimes in photoemission from solids. Science 353, 62–67 (2016).

    ADS  MathSciNet  Article  MATH  Google Scholar 

  8. 8.

    Niikura, H. et al. Sub-laser-cycle electron pulses for probing molecular dynamics. Nature 417, 917–922 (2002).

    ADS  Article  Google Scholar 

  9. 9.

    Itatani, J. et al. Tomographic imaging of molecular orbitals. Nature 432, 867–871 (2004).

    ADS  Article  Google Scholar 

  10. 10.

    Blaga, C. I. et al. Imaging ultrafast molecular dynamics with laser-induced electron diffraction. Nature 483, 194–197 (2012).

    ADS  Article  Google Scholar 

  11. 11.

    Wolter, B. et al. Ultrafast electron diffraction imaging of bond breaking in di-ionized acetylene. Science 354, 308–312 (2016).

    ADS  Article  Google Scholar 

  12. 12.

    Schneider, W. et al. 800-fs, 330-µJ pulses from a 100-W regenerative Yb:YAG thin-disk amplifier at 300 kHz and THz generation in LiNbO3. Opt. Lett. 39, 6604–6607 (2014).

    ADS  Article  Google Scholar 

  13. 13.

    Kealhofer, C. et al. All-optical control and metrology of electron pulses. Science 352, 429–433 (2016).

    ADS  MathSciNet  Article  MATH  Google Scholar 

  14. 14.

    Kirchner, F. O., Gliserin, A., Krausz, F. & Baum, P. Laser streaking of free electrons at 25 keV. Nat. Photonics 8, 52–57 (2014).

    ADS  Article  Google Scholar 

  15. 15.

    Priebe, K. E. et al. Attosecond electron pulse trains and quantum state reconstruction in ultrafast transmission electron microscopy. Preprint at (2017).

    ADS  Article  Google Scholar 

  16. 16.

    Barwick, B., Flannigan, D. J. & Zewail, A. H. Photon-induced near-field electron microscopy. Nature 462, 902–906 (2009).

    ADS  Article  Google Scholar 

  17. 17.

    Baum, P. & Zewail, A. H. Attosecond electron pulses for 4D diffraction and microscopy. Proc. Natl Acad. Sci. USA 104, 18409–18414 (2007).

    ADS  Article  Google Scholar 

  18. 18.

    Sears, C. M. S. et al. Production and characterization of attosecond electron bunch trains. Phys. Rev. Spec. Top. Accel. Beams 11, 061301 (2008).

    ADS  Article  Google Scholar 

  19. 19.

    Feist, A. et al. Quantum coherent optical phase modulation in an ultrafast transmission electron microscope. Nature 521, 200 (2015).

    ADS  Article  Google Scholar 

  20. 20.

    Kozak, M. et al. Optical gating and streaking of free electrons with sub-optical cycle precision. Nat. Commun. 8, 14342 (2017).

    ADS  Article  Google Scholar 

  21. 21.

    Gliserin, A., Walbran, M., Krausz, F. & Baum, P. Sub-phonon-period compression of electron pulses for atomic diffraction. Nat. Commun. 6, 8723 (2015).

    ADS  Article  Google Scholar 

  22. 22.

    Engelen, W. J., van der Heijden, M. A., Bakker, D. J., Vredenbregt, E. J. D. & Luiten, O. J. High-coherence electron bunches produced by femtosecond photoionization. Nat. Commun. 4, 1693 (2013).

    Article  Google Scholar 

  23. 23.

    Shao, H. C. & Starace, A. F. Detecting electron motion in atoms and molecules. Phys. Rev. Lett. 105, 263201 (2010).

    ADS  Article  Google Scholar 

  24. 24.

    Yakovlev, V. S., Stockman, M. I., Krausz, F. & P. Baum, P. Atomic-scale diffractive imaging of sub-cycle electron dynamics in condensed matter. Sci. Rep. 5, 14581 (2015).

    ADS  Article  Google Scholar 

  25. 25.

    Stingl, J. et al. Electron transfer in a virtual quantum state of LiBH4 induced by strong optical fields and mapped by femtosecond x-ray diffraction. Phys. Rev. Lett. 109, 147402 (2012).

    ADS  Article  Google Scholar 

  26. 26.

    Morimoto, Y., Kanya, R. & Yamanouchi, K. Light-dressing effect in laser-assisted elastic electron scattering by Xe. Phys. Rev. Lett. 115, 123201 (2015).

    ADS  Article  Google Scholar 

  27. 27.

    Cavalieri, A. L. et al. Attosecond spectroscopy in condensed matter. Nature 449, 1029–1032 (2007).

    ADS  Article  Google Scholar 

  28. 28.

    Eckle, P. et al. Attosecond ionization and tunneling delay time measurements in helium. Science 322, 1525–1529 (2008).

    ADS  Article  Google Scholar 

  29. 29.

    Schultze, M. et al. Delay in photoemission. Science 328, 1658–1662 (2010).

    ADS  Article  Google Scholar 

  30. 30.

    Klunder, K. et al. Probing single-photon ionization on the attosecond time scale. Phys. Rev. Lett. 106, 143002 (2011).

    ADS  Article  Google Scholar 

  31. 31.

    Neppl, S. et al. Direct observation of electron propagation and dielectric screening on the atomic length scale. Nature 517, 342–346 (2015).

    ADS  Article  Google Scholar 

  32. 32.

    Ryabov, A. & Baum, P. Electron microscopy of electromagnetic waveforms. Science 353, 374–377 (2016).

    ADS  Article  Google Scholar 

  33. 33.

    Kasmi, L., Kreier, D., Bradler, M., Riedle, E. & Baum, P. Femtosecond single-electron pulses generated by two-photon photoemission close to the work function. New J. Phys. 17, 033008 (2015).

    ADS  Article  Google Scholar 

  34. 34.

    Baum, P., Lochbrunner, S., Piel, J. & Riedle, E. Phase-coherent generation of tunable visible femtosecond pulses. Opt. Lett. 28, 185 (2003).

    ADS  Article  Google Scholar 

  35. 35.

    Waldecker, L., Bertoni, R. & Ernstorfer, R. Compact femtosecond electron diffractometer with 100 keV electron bunches approaching the single-electron pulse duration limit. J. Appl. Phys. 117, 044903 (2015).

    ADS  Article  Google Scholar 

  36. 36.

    Gerbig, C., Senftleben, A., Morgenstern, S., Sarpe, C. & Baumert, T. Spatio-temporal resolution studies on a highly compact ultrafast electron diffractometer. New J. Phys. 17, 043050 (2015).

    ADS  Article  Google Scholar 

  37. 37.

    Baum, P. & Zewail, A. H. 4D attosecond imaging with free electrons: Diffraction methods and potential applications. Chem. Phys. 366, 2–8 (2009).

    ADS  Article  Google Scholar 

  38. 38.

    Lahme, S., Kealhofer, C., Krausz, F. & Baum, P. Femtosecond single-electron diffraction. Struct. Dyn. 1, 034303 (2014).

    Article  Google Scholar 

  39. 39.

    Gonze, X. et al. ABINIT: First-principles approach to material and nanosystem properties. Comput. Phys. Commun. 180, 2582–2615 (2009).

    ADS  Article  Google Scholar 

  40. 40.

    Schultze, M. et al. Attosecond band-gap dynamics in silicon. Science 346, 1348–1352 (2014).

    ADS  Article  Google Scholar 

  41. 41.

    Shibata, N. et al. Differential phase-contrast microscopy at atomic resolution. Nat. Phys. 8, 611–615 (2012).

    Article  Google Scholar 

  42. 42.

    Mueller, K. et al. Atomic electric fields revealed by a quantum mechanical approach to electron picodiffraction. Nat. Commun. 5, 5653 (2014).

    Article  Google Scholar 

  43. 43.

    Weninger, C. & Baum, P. Temporal distortions in magnetic lenses. Ultramicroscopy 113, 145–151 (2012).

    Article  Google Scholar 

  44. 44.

    Kreier, D., Sabonis, D. & Baum, P. Alignment of magnetic solenoid lenses for minimizing temporal distortions. J. Optics 16, 075201 (2014).

    ADS  Article  Google Scholar 

  45. 45.

    Drescher, M. et al. Time-resolved atomic inner-shell spectroscopy. Nature 419, 803–807 (2002).

    ADS  Article  Google Scholar 

  46. 46.

    Reckenthaeler, P. et al. Proposed method for measuring the duration of electron pulses by attosecond streaking. Phys. Rev. A 77, 042902 (2008).

    ADS  Article  Google Scholar 

  47. 47.

    Garg, M. et al. Multi-petahertz electronic metrology. Nature 538, 359–363 (2016).

    ADS  Article  Google Scholar 

  48. 48.

    Mashiko, H., Oguri, K., Yamaguchi, T., Suda, A. & Gotoh, H. Petahertz optical drive with wide-bandgap semiconductor. Nat. Phys. 12, 741–745 (2016).

    Article  Google Scholar 

  49. 49.

    Hohenleutner, M. et al. Real-time observation of interfering crystal electrons in high-harmonic generation. Nature 523, 572 (2015).

    ADS  Article  Google Scholar 

  50. 50.

    Vampa, G. et al. Linking high harmonics from gases and solids. Nature 522, 462 (2015).

    ADS  Article  Google Scholar 

  51. 51.

    Luu, T. T. et al. Extreme ultraviolet high-harmonic spectroscopy of solids. Nature 521, 498–502 (2015).

    ADS  Article  Google Scholar 

  52. 52.

    Ndabashimiye, G. et al. Solid-state harmonics beyond the atomic limit. Nature 534, 520 (2016).

    ADS  Article  Google Scholar 

  53. 53.

    Schiffrin, A. et al. Optical-field-induced current in dielectrics. Nature 493, 70–74 (2013).

    ADS  Article  Google Scholar 

  54. 54.

    Schultze, M. et al. Controlling dielectrics with the electric field of light. Nature 493, 75–78 (2013).

    ADS  Article  Google Scholar 

  55. 55.

    Carbone, F., Kwon, O.-H. & Zewail, A. H. Dynamics of chemical bonding mapped by energy-resolved 4D electron microscopy. Science 325, 181–184 (2009).

    ADS  Article  Google Scholar 

  56. 56.

    van der Veen, R. M., Penfold, T. J. & Zewail, A. H. Ultrafast core-loss spectroscopy in four-dimensional electron microscopy. Struct. Dyn. 2, 024302 (2015).

    Article  Google Scholar 

  57. 57.

    Verhoeven, W. et al. Time-of-flight electron energy loss spectroscopy using tm110 deflection cavities. Struct. Dyn. 3, 054303 (2016).

    Article  Google Scholar 

  58. 58.

    Zhou, F., Williams, J. & Ruan, C.-Y. Femtosecond electron spectroscopy in an electron microscope with high brightness beams. Chem. Phys. Lett. 683, 488–494 (2017).

    ADS  Article  Google Scholar 

Download references


This work was supported by the European Research Council (grant DIVI) and the Munich-Centre for Advanced Photonics. Y.M. acknowledges support from a JSPS Postdoctoral Fellowship for Research Abroad. We thank B.-H. Chen and A. Ryabov for help with the laser, S. Stork for help with the foils and F. Krausz for awesome support and inspiring discussions.

Author information




Y.M. and P.B. conceived the experiment, Y.M. measured the data, Y.M. and P.B. evaluated the data and Y.M. and P.B. wrote the manuscript.

Corresponding author

Correspondence to Peter Baum.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Electronic supplementary material

Supplementary Information

Supplementary Figure 1

Supplementary Video 1

Attosecond electron microscopy of a traveling wave. The left panel shows the raw microscopic image of the silicon window in time. The right panel shows the change of the images with respect to the excitation delay. The scale bars represent 100 µm

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Morimoto, Y., Baum, P. Diffraction and microscopy with attosecond electron pulse trains. Nature Phys 14, 252–256 (2018).

Download citation

Further reading


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing