Custom X-Ray Lenses Aid Astrophysical Imaging

Dr. Flavio Fontana

The National Research Council's Solid State Electronics Institute is producing custom optics for scientists who want to develop their own x-ray optical systems for astrophysical investigation or synchrotron radiation research.

Researchers rely on nanolithography to manufacture zone plates with 10- to 100-nm features. However, the facilities that have these capabilities are seldom available or affordable for small production runs. The technology developed at the institute allows for excellent reproducibility because the zone-plate pattern is recorded with only one layer of resist, thus avoiding intermediate etching steps that reduce process yield.

An x-ray lens based on submicron zone-plate technology can focus at shorter wavelengths.

Using a proprietary modified Leica-Cambridge 50-keV e-beam system, the institute has demonstrated zone plates with 10-nm features. The optics have been successfully applied in biology studies and material diagnostics. Two facilities using these optics in their research are the European Synchrotron Radiation Facility of Grenoble, France, which is owned by a consortium of European government administrations, and Advanced Light Sources, a synchrotron radiation facility operated by the University of California at Berkeley.

The institute also has demonstrated a proprietary technique that allows fabrication of continuously varying profiles that could further enhance the efficiency of light diffraction. This additional degree of freedom enables the design of optical elements that are much more complex than Fresnel plates.

An Italian high-tech firm, GMT SrL, markets the x-ray optics and has collaborated with the institute in developing the control software used in the electron beam facility. Both also offer specialized consulting services in nanotechnologies applied to optical research.