A Shack–Hartmann measuring head for the two‐dimensional characterization of X‐ray mirrors

The recent development of short‐wavelength optics (X/EUV, synchrotrons) requires improved metrology techniques in terms of accuracy and curvature dynamic range. In this article a stitching Shack–Hartmann head dedicated to be mounted on translation stages for the characterization of X‐ray mirrors is presented. The principle of the instrument is described and experimental results for an X‐ray toroidal mirror are presented. Submicroradian performances can be achieved and systematic comparison with a classical long‐trace profiler is presented. The accuracy and wide dynamic range of the Shack–Hartmann long‐trace‐profiler head allow two‐dimensional characterizations of surface figure and curvature with a submillimeter spatial resolution.