Microstitching interferometry for x-ray reflective optics

Abstract

Relative angle determinable stitching interferometry for hard x-ray reflective optics Rev. Sci. Instrum. 76, 045102 (2005); 10.1063/1.1868472 X-ray wavefront analysis and optics characterization with a grating interferometer A new stitching interferometry based on a microscopic interferometer having peak-to-valley height accuracy of subnanometer order and lateral resolution higher than 20 m 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 1ϫ10 Ϫ7 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 ͑BL29XUL͒ of SPring-8. Observed and wave optically calculated results were in good agreement with a high degree of accuracy.

Optics for coherent X-ray applications

“…In this subsection, we review high-quality mirrors developed at SPring-8. In 2001, we started to fabricate flat mirrors by combining EEM with a micro-stitching interferometer (MSI) (Yamauchi et al, 2003). We achieved a flat intensity profile without speckles as shown in Fig.…”

“…In addition, figure errors with a spatial period in the sub-millimetre region should be sufficiently suppressed in order to produce a uniform intensity profile (Mimura et al, 2004;Yamauchi et al, 2005). To achieve this level, several machining techniques have been developed, such as elastic emission machining (EEM) (Yamauchi et al, 2002a), ion beam figuring (Schindler et al, 2001) and additional deposition (Ice et al, 2000), as well as surface metrologies such as a long trace profiler (Takacs et al, 1987) and stitching interferometers (Yamauchi et al, 2003;Mimura et al, 2005a). Recently, one could achieve a high figure accuracy and small degree of roughness of 1 nm (peak to valley) and 0.2 nm (r.m.s.…”

Ultra-precise characterization of LCLS hard X-ray focusing mirrors by high resolution slope measuring deflectometry

“…Interferometric sub-aperture stitching metrology [33] was applied by the manufacturer to control the level of figure accuracy achieved during the different steps of deterministic polishing and for the final acceptance tests. The task of the verification in Berlin was to give an independent third-party cross-check of the mirrors shape by use of a different measuring method.…”

Nano-Accuracy Surface Figure Metrology of Precision Optics

“…Measurement error repeatability has been demonstrated to be 2 nm rms. Relative angle determinable stitching interferometry (RADSI) was also developed by the Osaka University group to measure steeply curved X-ray mirrors with nanometer accuracy (Mimura et al, 2005;Yamauchi et al, 2003;Yumoto et al, 2010). In this method, the relative angles between overlapping sub-apertures are determined simultaneously with one interferometer while acquiring the sub-aperture profiles with another.…”