Microstitching interferometry for x-ray reflective optics

A new stitching interferometry based on a microscopic interferometer having peak-to-valley height accuracy of subnanometer order and lateral resolution higher than 20 μm was developed to measure surface figures of large-size x-ray mirror optics. Cumulative errors of the stitching angle in a long spatial wavelength range were effectively reduced to be 1×10−7 rad levels using another interferometer having a large cross section in the optical cavity. Some optical performances of ultraprecise x-ray mirrors, such as submicrofocused beam profile, were wave optically calculated from the measured surface figure profiles and observed at the 1 km long beamline (BL29XUL) of SPring-8. Observed and wave optically calculated results were in good agreement with a high degree of accuracy.Kazuto Yamauchi, Kazuya Yamamura, Hidekazu Mimura, Yasuhisa Sano, Akira Saito, Kazumasa Ueno, Katsuyoshi Endo, Alexei Souvorov, Makina Yabashi, Kenji Tamasaku, Tetsuya Ishikawa and Yuzo Mori, "Microstitching interferometry for x-ray reflective optics", Review of Scientific Instruments 74, 2894-2898 (2003) https://doi.org/10.1063/1.1569405