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.

Challenges and opportunities for the next decade of XFELs

The first decade of X-ray free-electron lasers (XFELs) has led to technological advances and scientific discoveries, but has also highlighted several facility-level challenges. Chi-Chang Kao, Director of SLAC, discusses the lessons to be learned from the first 10 years of operation and shares his thoughts on how facilities can overcome challenges facing XFEL development.

Your institute does not have access to this article

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. Pellegrini, C. The history of x-ray free-electron laser. Eur. Phys. J. H 37, 659–708 (2012).

    Article  Google Scholar 

  2. Bostedt, C. et al. Linac Coherent Light Source: the first five years. Rev. Mod. Phys. 88, 015007 (2016).

    ADS  Article  Google Scholar 

  3. Bergmann, U., Yachandra, V. & Yano, J. (eds) X-Ray Free Electron Lasers: Applications in Materials, Chemistry and Biology (RSC, 2017).

  4. Schoenlein, R. W., Boutet, S., Minitti, M. P. & M. Dunne, M. The Linac Coherent Light Source: recent developments and future plans. Appl. Sci. 7, 850 (2017).

    Article  Google Scholar 

  5. Boutet, S., Fromme, P. & Hunter, M. X-Ray Free Electron Lasers: A Revolution in Structural Biology (Springer, 2018).

  6. Schoenlein, R. et al. New science opportunities enabled by LCLS-II X-ray lasers. SLAC-R-1053 (2016).

Download references


The author thanks XFEL facility directors around the world for sharing their experiences and thinking over the years and M. Dunne and J. Hastings for reading the article and the discussions on this topic. SLAC is operated by Stanford University for the US Department of Energy’s (DOE) Office of Science. The Office of Science is the single largest supporter of basic research in the physical sciences in the USA. LCLS is a DOE Office of Science user facility.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Chi-Chang Kao.

Ethics declarations

Competing interests

The author declares no competing interests.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Kao, CC. Challenges and opportunities for the next decade of XFELs. Nat Rev Phys 2, 340–341 (2020).

Download citation

  • Published:

  • Issue Date:

  • DOI:

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