Title: Intrinsic resolving power of XUV diffraction gratings measured with Fizeau interferometry,
Abstract: We introduce a method for using Fizeau interferometry to measure the
intrinsic resolving power of a diffraction grating. This method is more
accurate than traditional techniques based on a long-trace profiler (LTP),
since it is sensitive to long-distance phase errors not revealed by a d-spacing
map. We demonstrate 50,400 resolving power for a mechanically ruled XUV grating
from Inprentus, Inc.