LAUSR

Abstract With the fast development of diffraction-limited storage rings and free electron lasers, the requirement for ultimate quality X-ray mirror is getting higher and the mirror surface needs to approach the sub-nm root mean square height specifications. These ultimate specifications challenge the X-ray mirror metrology community. In this work, we present our developed dedicated stitching metrology platform for X-ray mirror metrology. Various stitching methods with different stitching parameters are investigated in our stitching interferometric system. Some experimental results are given to demonstrate its validity and performance. According to the measurement results, the repeatability of measuring a flat mirror in the software stitching mode is at 0.1 nm RMS level. In relative angle determinable stitching mode when measuring a curved mirror with its radius of curvature varying from 50 m to 175 m, the repeatability is around 1 nm RMS.