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.

You are viewing this page in draft mode.

A stacked prism lens concept for next-generation hard X-ray telescopes


Effective collecting area, angular resolution, field of view and energy response are fundamental attributes of X-ray telescopes. The performance of state-of-the-art telescopes is currently restricted by Wolter optics, especially for hard X-rays. Here we report the development of a stacked prism lens (SPL), which is lightweight and modular and has the potential for a significant improvement in effective area, while retaining high angular resolution. The proposed optics are built by stacking disks embedded with prismatic rings, created with photoresist by focused ultraviolet lithography. We demonstrate the SPL approach using a prototype lens that was manufactured and characterized at a synchrotron radiation facility. The design of a potential satellite-borne X-ray telescope is outlined and the performance is compared with contemporary missions.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Illustration of the proposed SPL.
Fig. 2: Main fabrication process steps of the disks for the SPL (not to scale).
Fig. 3: The fabricated disks and completed SPL.
Fig. 4: Experimental and simulated performance of the SPL.
Fig. 5: Implementation of a hard X-ray focusing telescope based on the SPL array.

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.

    Karouzos, M. X-ray astronomy: black holes in the sky with Chandra. Nat. Astron. 1, 0046 (2017).

    ADS  Article  Google Scholar 

  2. 2.

    Gorenstein, P. Focusing X-ray optics for astronomy. X-Ray Opt. Instrum. 2010, 109740 (2010).

    Google Scholar 

  3. 3.

    Weisskopf, M. C., Tananbaum, H. D., Van Speybroeck, L. P. & O’Dell, S. L. Chandra X-ray observatory (CXO): overview. Proc. SPIE 4012, 2–17 (2000).

    ADS  Article  Google Scholar 

  4. 4.

    Jansen, F. et al. XMM-Newton observatory—I. The spacecraft and operations. Astron. Astrophys. 365, L1–L6 (2001).

    ADS  Article  Google Scholar 

  5. 5.

    Gehrels, N. et al. The Swift gamma-ray burst mission. Astrophys. J. 611, 1005–1020 (2004).

    ADS  Article  Google Scholar 

  6. 6.

    Nandra, K. et al. The hot and energetic universe: a white paper presenting the science theme motivating the Athena+ mission. Preprint at (2013).

  7. 7.

    Koglin, J. E. et al. NuSTAR hard X-ray optics design and performance. Proc. SPIE 7437, 74370C (2004).

    Article  Google Scholar 

  8. 8.

    Koglin, J. E. et al. Development and production of hard X-ray multilayer optics for HEFT. Proc. SPIE 4851, 607–619 (2003).

    ADS  Article  Google Scholar 

  9. 9.

    Harrison, F. A. et al. The nuclear spectroscopic telescope array (NuSTAR) high-energy X-ray mission. Astrophys. J. 770, 103–122 (2013).

    ADS  Article  Google Scholar 

  10. 10.

    Takahashi, T. et al. The ASTRO-H X-ray. Obs. Proc. SPIE 8443, 84431Z (2012).

    Article  Google Scholar 

  11. 11.

    Awaki, H. et al. The Hitomi (ASTRO-H) hard X-ray telescope (HXT): current status of calibration. Proc. SPIE 10399, 103990R (2017).

    Google Scholar 

  12. 12.

    Cederström, B., Cahn, R. N., Danielsson, M., Lundqvist, M. & Nygren, D. R. Focusing hard X-rays with old LPs. Nature 404, 951 (2000).

    ADS  Article  Google Scholar 

  13. 13.

    Snigirev, A., Kohn, V., Snigireva, I. & Lengeler, B. A compound refractive lens for focusing high-energy X-rays. Nature 384, 49–51 (1996).

    ADS  Article  Google Scholar 

  14. 14.

    Chang, C. & Sakdinawat, A. Ultra-high aspect ratio high-resolution nanofabrication for hard X-ray diffractive optics. Nat. Commun. 5, 4243 (2014).

    ADS  Article  Google Scholar 

  15. 15.

    Sakdinawat, A. & Attwood, D. Nanoscale X-ray imaging. Nat. Photon. 4, 840–848 (2010).

    ADS  Article  Google Scholar 

  16. 16.

    Chao, W., Harteneck, B. D., Liddle, J. A., Anderson, E. H. & Attwood, D. T. Soft X-ray microscopy at a spatial resolution better than 15 nm. Nature 435, 1210–1213 (2005).

    ADS  Article  Google Scholar 

  17. 17.

    Di Fabrizio, E. et al. High-efficiency multilevel zone plates for keV X-rays. Nature 401, 895–898 (1999).

    ADS  Article  Google Scholar 

  18. 18.

    Schneider, G. et al. Three-dimensional cellular ultrastructure resolved by X-ray microscopy. Nat. Methods 7, 985–987 (2010).

    Article  Google Scholar 

  19. 19.

    Shapiro, D. A. et al. Chemical composition mapping with nanometre resolution by soft X-ray microscopy. Nat. Photon. 8, 765–769 (2014).

    ADS  Article  Google Scholar 

  20. 20.

    Leontowich, A. F. & Hitchcock, A. P. Zone plate focused soft X-ray lithography. Appl. Phys. A 103, 1–11 (2011).

    ADS  Article  Google Scholar 

  21. 21.

    Larciprete, R. et al. Direct writing of fluorescent patterns on LiF films by X-ray microprobe. Appl. Phys. Lett. 80, 3862–3864 (2002).

    ADS  Article  Google Scholar 

  22. 22.

    Keskinbora, K. et al. Multilayer Fresnel zone plates for high energy radiation resolve 21 nm features at 1.2 keV. Opt. Express 22, 18440–18453 (2014).

    ADS  Article  Google Scholar 

  23. 23.

    Kang, H. C. et al. Focusing of hard X-rays to 16 nanometers with a multilayer Laue lens. Appl. Phys. Lett. 92, 221114 (2008).

    ADS  Article  Google Scholar 

  24. 24.

    Huang, X. et al. 11 nm hard X-ray focus from a large-aperture multilayer Laue lens. Sci. Rep. 3, 3562 (2013).

    Article  Google Scholar 

  25. 25.

    Kang, H. et al. Nanometer linear focusing of hard X rays by a multilayer Laue lens. Phys. Rev. Lett. 96, 127401 (2006).

    ADS  Article  Google Scholar 

  26. 26.

    Mohacsi, I. et al. Interlaced zone plate optics for hard X-ray imaging in the 10 nm range. Sci. Rep. 7, 43624 (2017).

    ADS  Article  Google Scholar 

  27. 27.

    Maser, J. et al. Near-field stacking of zone plates for hard X-ray range. Proc. SPIE 4783, 74–82 (2002).

    ADS  Article  Google Scholar 

  28. 28.

    Skinner, G. Diffractive-refractive optics for high energy astronomy—I. Gamma-ray phase Fresnel lenses. Astron. Astrophys. 375, 691–700 (2001).

    ADS  Article  Google Scholar 

  29. 29.

    Skinner, G. K. Diffractive-refractive optics for high energy astronomy—II. Variations on the theme. Astron. Astrophys. 383, 352–359 (2002).

    ADS  Article  Google Scholar 

  30. 30.

    Skinner, G. et al. The milli-arc-second structure imager (MASSIM): a new concept for a high angular resolution X-ray telescope. Proc. SPIE 7011, 70110T (2008).

    Article  Google Scholar 

  31. 31.

    Braig, C. & Predehl, P. Fresnel lens arrays for X-ray imaging spectroscopy. Proc. SPIE 7732, 77322N (2010).

    ADS  Google Scholar 

  32. 32.

    Braig, C. & Predehl, P. Multiband imaging with Fresnel X-ray telescopes. Proc. SPIE 7732, 77322M (2010).

    ADS  Google Scholar 

  33. 33.

    Mi, W., Karlsson, S., Holmberg, A., Danielsson, M. & Nillius, P. Fabrication of circular sawtooth gratings using focused UV lithography. J. Micromech. Microeng. 26, 035001 (2016).

    ADS  Article  Google Scholar 

  34. 34.

    Cederström, B., Ribbing, C. & Lundqvist, M. Generalized prism-array lenses for hard X-rays. J. Synchrotron Radiat. 12, 340–344 (2005).

    Article  Google Scholar 

  35. 35.

    Jark, W. et al. Focusing X-rays with simple arrays of prism-like structures. J. Synchrotron Radiat. 11, 248–253 (2004).

    Article  Google Scholar 

  36. 36.

    Nillius, P., Karlsson, S., Cederström, B., Fredenberg, E. & Danielsson, M. Large-aperture focusing of high-energy X rays with a rolled polyimide film. Opt. Lett. 36, 555–557 (2011).

    ADS  Article  Google Scholar 

  37. 37.

    Jark, W., Matteucci, M., Menk, R., Rigon, L. & De Caro, L. The role of spatial coherence, diffraction and refraction in the focusing of X-rays with prism arrays of the Clessidra type. Proc. SPIE 7077, 70771× (2008).

    ADS  Article  Google Scholar 

  38. 38.

    Mi, W. & Nillius, P. Efficient proximity effect correction method based on multivariate adaptive regression splines for grayscale e-beam lithography. J. Vac. Sci. Technol. B 32, 031602 (2014).

    Article  Google Scholar 

  39. 39.

    Fossum, E. R. CMOS image sensors: electronic camera-on-a-chip. IEEE Trans. Electron Devices 44, 1689–1698 (1997).

    ADS  Article  Google Scholar 

  40. 40.

    Soltau, H. et al. Fabrication, test and performance of very large X-ray CCDs designed for astrophysical applications. Nucl. Instrum. Methods Phys. Res. A 439, 547–559 (2000).

    ADS  Article  Google Scholar 

  41. 41.

    Skinner, G. K. Design and imaging performance of achromatic diffractive–refractive X-ray and gamma-ray Fresnel lenses. Appl. Opt. 43, 4845–4853 (2004).

    ADS  Article  Google Scholar 

  42. 42.

    Wang, Y., Yun, W. & Jacobsen, C. Achromatic Fresnel optics for wideband extreme-ultraviolet and X-ray imaging. Nature 424, 50–53 (2003).

    ADS  Article  Google Scholar 

  43. 43.

    Marschall, F. et al. X-ray full field microscopy at 30 keV. J. Phys. Conf. Ser. 499, 012007 (2014).

    Article  Google Scholar 

  44. 44.

    Tibbelin, S., Nillius, P. & Danielsson, M. Simulation of HyperSPECT: a high-resolution small-animal system with in-line X-ray optics. Phys. Med. Biol. 57, 1617–1629 (2012).

    Article  Google Scholar 

  45. 45.

    Cederström, B. A Multi-prism Lens for Hard X-rays. PhD thesis, KTH Royal Institute of Technology (2002).

  46. 46.

    Nillius, P. Geometric scattering in prism-array lenses for hard X-rays: measurements, simulations and models. AIP Conf. Proc. 1437, 111–115 (2012).

    ADS  Article  Google Scholar 

  47. 47.

    Lengeler, B. et al. Imaging by parabolic refractive lenses in the hard X-ray range. J. Synchrotron Radiat. 6, 1153–1167 (1999).

    Article  Google Scholar 

Download references


We thank the KTH nanolab for access to the fabrication devices and support during fabrication. We acknowledge the Diamond Light Source for provision of synchrotron radiation facilities and express our thanks to O. Fox and K. Sawhney for assistance in applying and using beamline B16. We thank C. Xu and S. Karlsson for taking part in the experiment at the Diamond Light Source, C. Svensson for the detector design and power calculation and L. Mi for X-ray telescope concept drawing. W.M and M.D. acknowledge funding from Stiftelsen Olle Engkvist Byggmästare. M.P. acknowledges funding received from the Swedish Research Council (grant number 2016-04929).

Author information




W.M. performed the design, fabrication, test experiments and simulation of the stacked prism lens, analysed the experiment data and space application, and prepared the paper. P.N. contributed to the design of stacked prism lens and the development of the simulation programme, performed the X-ray experiments and discussed the experiment results. M.P. discussed and developed the space application of stacked prism lenses and assisted with the writing of the manuscript. M.D. managed the project, proposed applications for space and other areas and together with the co-authors coordinated the writing of the manuscript.

Corresponding author

Correspondence to Wujun Mi.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information: Nature Astronomy thanks Ralf Heilmann, Julia Vogel and the other anonymous reviewer(s) for their contribution to the peer review of this work.

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

Supplementary information

Supplementary Information

Supplementary Figs. 1–8.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Mi, W., Nillius, P., Pearce, M. et al. A stacked prism lens concept for next-generation hard X-ray telescopes. Nat Astron 3, 867–872 (2019).

Download citation


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