The SPO optics are modules that consist of pairs of stacked X-ray mirrors that together form a small X-ray lens. The modules have very low mass compared to other X-ray optics technology with similar imaging resolution.

While each module is an off-axis lens in itself, many modules can be combined to form a much larger X-ray lens for X-ray astronomy, X-ray Earth observation and ground-based X-ray instrumentation.

X-ray telescopes

SPO is the baseline technology for ESA’s future space based X-ray telescope ATHENA. The low mass of SPO makes it possible to build unprecedented large X-ray lenses cost-effectively, yielding several square meters of effective area. It is a factor 10 lighter than present-day technologies such as the XMM Newton telescope optics, which are made from metal. The modularity of SPO allows for a very large (3m diameter is planned, much larger could be made) X-ray optics, with better optical quality compared to currently flying X-ray telescope.

At smaller sizes, other lightweight instrument applications are possible, such as pulsar navigation (see Further Reading below)


  • X-ray astronomy
  • Pulsar navigation
  • Nuclear explosions and cosmic particles in Earth atmosphere
  • Beam line, medical, and material analysis X-ray equipment


  • Effective collecting area per module@ 1 keV: 12 cm2 at 0.4 kg
  • Imaging resolution under 15 arcsec
  • Focal lengths between 12 m and 50 m have been demonstrated. Other focal lengths are possible, please inquire.
  • Radii of functional optics have been demonstrated from 250mm to 2000mm. Other radii are possible, please inquire.
  • Coatings in Ir, Pt, or Au, provide good response up to 8 keV
  • Optional multilayers, are capable of boosting response to 30-60 keV


  • Technology has TRL 4 for space applications
  • Built to order
  • Delivery time 1 week per module
  • Lead time for focal length other than 15 m is 9 months
  • Image resolution below 15 arcsec is under development


For more information please

Contact Dipl.-Ing Max Collon.