Fabricating the Next Generation of High Energy Reflection Gratings

Encoded in far-UV and soft-X-ray spectra is information about the atmospheric compositions of planets and signposts of habitability, stellar life cycles, and energetic processes of the early universe. Due to the need to analyze this light in specific, highly resolved wavelength regions, the next generation of UV/X-ray spectrographs will require excellent sensitivity while maintaining high spectral resolution. For these reasons, UV gratings remain a high-priority technology for development. Advancements made in X-ray grating fabrication have demonstrated electron beam lithography (EBL) in combination with potassium hydroxide (KOH) wet-etching is a promising technique for fabricating efficient, high-resolution blazed diffraction gratings, while nanoimprint lithography (NIL) may be a cost-effective way to realize the quantities of gratings needed for flight. We use each of these techniques, available at the University of Iowa Materials Analysis, Testing and Fabrication (MATFab) Facility, to manufacture gratings and we report on our progress implementing these techniques to fulfill the technical requirements of the next generation of high-energy reflection gratings.