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.

Towards jitter-free ultrafast electron diffraction technology


Stroboscopic visualization of nuclear or electron dynamics in atoms, molecules or solids requires ultrafast pump and probe pulses and a close to perfect synchronization between the two. We have developed a 3 MeV ultrafast electron diffraction (UED) probe technology that nominally reduces the electron bunch duration and the arrival time jitter to the subfemtosecond level. This simple configuration uses a radiofrequency photogun and a 90° achromatic bend and is designed to provide effectively jitter-free conditions. Terahertz streaking measurements reveal an electron bunch duration of 25 fs, even for a charge as high as 0.6 pC, and an arrival time jitter of 7.8 fs, the latter limited by only the measurement accuracy. From pump–probe measurements of photoexcited bismuth films, the instrument response function was determined to be 31 fs. This pioneering jitter-free technique paves the way towards UED of attosecond phenomena in atomic, molecular and solid-state dynamics.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Schematic of the UED beamline and simulated temporal characteristics of an electron bunch.
Fig. 2: Simulated arrival time jitter of electron beams.
Fig. 3: THz streaking experiment.
Fig. 4: Comparison of the simulated and measured electron bunch duration and jitter.
Fig. 5: Dynamics of the (300) peak intensities of polycrystalline Bi.

Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.


  1. 1.

    Emma, P. et al. First lasing and operation of an angstrom-wavelength free-electron laser. Nat. Photon. 4, 641–647 (2010).

    ADS  Article  Google Scholar 

  2. 2.

    Ishikawa, T. et al. A compact X-ray free-electron laser emitting in the sub-angstrom region. Nat. Photon. 6, 540–544 (2012).

    ADS  Article  Google Scholar 

  3. 3.

    Kang, H.-S. et al. Hard X-ray free-electron laser with femtosecond-scale timing jitter. Nat. Photon. 11, 708–713 (2017).

    ADS  Article  Google Scholar 

  4. 4.

    Wang, X. J., Xiang, D., Kim, T. K. & Ihee, H. Potential of femtosecond electron diffraction using near-relativistic electrons from a photocathode RF electron gun. J. Korean Phys. Soc. 48, 390–396 (2006).

    Google Scholar 

  5. 5.

    Hasting, J. B. et al. Ultrafast time-resolved electron diffraction with megavolt electron beams. Appl. Phys. Lett. 89, 184109 (2006).

    ADS  Article  Google Scholar 

  6. 6.

    Musumeci, P., Moody, J. T., Scoby, C. M., Gutierrez, M. S. & Westfall, M. Laser-induced melting of a single crystal gold sample by time-resolved ultrafast relativistic electron diffraction. Appl. Phys. Lett. 97, 063502 (2010).

    ADS  Article  Google Scholar 

  7. 7.

    Murooka, Y. et al. Transmission-electron diffraction by MeV electron pulses. Appl. Phys. Lett. 98, 251903 (2011).

    ADS  Article  Google Scholar 

  8. 8.

    Manz, S. et al. Mapping atomic motion with ultrabright electrons: towards fundamental limits in space–time resolution. Faraday Discuss. 177, 467–491 (2015).

    ADS  Article  Google Scholar 

  9. 9.

    Weathersby, S. P. et al. Mega-electron-volt ultrafast electron diffraction at SLAC National Accelerator Laboratory. Rev. Sci. Instrum. 86, 073702 (2015).

    ADS  Article  Google Scholar 

  10. 10.

    Fritz, D. M. et al. Ultrafast bond softening in bismuth: mapping a solid’s interatomic potential with X-rays. Science 315, 633–636 (2007).

    ADS  Article  Google Scholar 

  11. 11.

    Harmand, A. et al. Achieving few-femtosecond time-sorting at hard X-ray free-electron lasers. Nat. Photon. 7, 215–218 (2013).

    ADS  Article  Google Scholar 

  12. 12.

    Maxson, J., Cesar, D., Calmasini, G., Ody, A. & Musumeci, P. Direct measurement of sub-10 fs relativistic electron beams with ultralow emittance. Phys. Rev. Lett. 118, 154802 (2017).

    ADS  Article  Google Scholar 

  13. 13.

    Zhao, L. et al. Terahertz streaking of few-femtosecond relativistic electron beams. Phys. Rev. X 8, 021061 (2018).

    Google Scholar 

  14. 14.

    Kim, H. W. et al. Performance of an indium-sealed S-band RF photoelectron gun for time-resolved electron diffraction experiments. J. Korean Phys. Soc. 74, 24–29 (2019).

    ADS  Article  Google Scholar 

  15. 15.

    Yang, H. et al. 10-fs-level synchronization of photocathode laser with RF-oscillator for ultrafast electron and X-ray sources. Sci. Rep. 7, 39966 (2017).

    ADS  Article  Google Scholar 

  16. 16.

    Casanova, A., D’Acremont, Q., Santarelli, G., Dilhaire, S. & Courjaud, A. Ultrafast amplifier additive timing jitter characterization and control. Opt. Lett. 41, 898–900 (2016).

    ADS  Article  Google Scholar 

  17. 17.

    Serafini, L. & Ferrario, M. Velocity bunching in photo-injectors. AIP Conf. Proc. 581, 87 (2001).

    ADS  Article  Google Scholar 

  18. 18.

    Fabianska, J., Kassier, G. & Feurer, T. Split ring resonator based THz-driven electron streak camera featuring femtosecond resolution. Sci. Rep. 4, 5645 (2014).

    ADS  Article  Google Scholar 

  19. 19.

    Bagiante, S., Enderli, F., Fabianska, J., Sigg, H. & Feurer, T. Giant electric field enhancement in split ring resonators featuring nanometer-sized gaps. Sci. Rep. 5, 8051 (2015).

    ADS  Article  Google Scholar 

  20. 20.

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

    ADS  MathSciNet  Article  Google Scholar 

  21. 21.

    Li, R. K. et al. Terahertz-based subfemtosecond metrology of relativistic electron beams. Phys. Rev. Accel. Beams 22, 012803 (2019).

    ADS  Article  Google Scholar 

  22. 22.

    Hebling, J., Almasi, G., Kozma, I. & Kuhl, J. Velocity matching by pulse front tilting for large area THz-pulse generation. Opt. Express 10, 1161–1166 (2002).

    ADS  Article  Google Scholar 

  23. 23.

    Winnewisser, C., Jepsen, P. U., Scnall, M., Schyja, V. & Helm, H. Electro-optic detection of THz radiation in LiTaO3, LiNbO3 and ZnTe. Appl. Phys. Lett. 70, 3069–3071 (1997).

    ADS  Article  Google Scholar 

  24. 24.

    Setiniyaz, S. et al. Beam characterization at the KAERI UED beamline. J. Korean Phys. Soc. 69, 1019–1024 (2016).

    ADS  Article  Google Scholar 

  25. 25.

    Shen, X. et al. Femtosecond mega-electron-volt electron microdiffraction. Ultramicroscopy 184, 172–176 (2018).

    Article  Google Scholar 

  26. 26.

    Lee, J. H. et al. Filming the birth of molecules and accompanying solvent rearrangement. J. Am. Chem. Soc. 135, 3255–3261 (2013).

    Article  Google Scholar 

  27. 27.

    Oang, K. Y. et al. Sub-100-ps structural dynamics of horse heart myoglobin probed by time-resolved X-ray solution scattering. Chem. Phys. 442, 137–142 (2014).

    Article  Google Scholar 

  28. 28.

    Kim, K. H. et al. Direct observation of bond formation in solution with femtosecond X-ray scattering. Nature 518, 385–389 (2015).

    ADS  Article  Google Scholar 

  29. 29.

    James, F. & Roos, M. Minuit—a system for function minimization and analysis of the parameter errors and correlations. Comput. Phys. Commun. 10, 343–367 (1975).

    ADS  Article  Google Scholar 

  30. 30.

    Williamson, J. C. & Zewail, A. H. Ultrafast electron diffraction. Velocity mismatch and temporal resolution in crossed-beam experiments. Chem. Phys. Lett. 209, 10–16 (1993).

    ADS  Article  Google Scholar 

  31. 31.

    Zhang, P., Yang, J. & Centurion, M. Tilted femtosecond pulses for velocity matching in gas-phase ultrafast electron diffraction. New J. Phys. 16, 083008 (2014).

    ADS  Article  Google Scholar 

  32. 32.

    Floettmann, K. ASTRA—a space charge tracking algorithm. (DESY, 2017).

Download references


This work was supported by the World Class Institute (WCI) Program of the National Research Foundation of Korea (NRF), funded by the Ministry of Science, ICT and Future Planning (NRF grant no. WCI 2011-001), and an internal R&D programme at KAERI funded by the Ministry of Science and ICT (MSIT) of the Republic of Korea (525350-19), and partially supported by the University of Science and Technology (UST) UST Young Scientist Research Program, through the University of Science and Technology (no. 2017-YS-06), and a National Research Council of Science & Technology (NST) grant by the Korea government (MSIT) (no. CAP-18-05-KAERI). T.F. acknowledges funding from the Swiss National Science Foundation (SNSF) under grant no. 200020-178812.

Author information




H.W.K., N.A.V., K.Y.O., K-H.J., S.H.P., S.P., T.F. and Y.U.J. carried out the UED and THz streaking experiment. I.H.B., M.H.K., Y.C.K., K.L. and F.R. led the THz and optical characterization experiments. J.S. and J.K. carried out the synchronization between the laser and RF signal. S.C. carried out the bismuth sample growth. H.W.K., N.A.V. and K.Y.O. carried out the simulations and performed the data analysis. H.W.K. and Y.U.J. wrote the manuscript, with input from all authors.

Corresponding author

Correspondence to Young Uk Jeong.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

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

Supplementary information

Supplementary Information

Supplementary Figs. 1 and 2, materials and methods, Table 1 and equations (1)–(6).

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Kim, H.W., Vinokurov, N.A., Baek, I.H. et al. Towards jitter-free ultrafast electron diffraction technology. Nat. Photonics 14, 245–249 (2020).

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