Cross-Test Results with SSI™ for High-Precision Sphere Measurements

Case Study Summary

This case study explores the accuracy and repeatability of QED Technologies’ Subaperture Stitching Interferometry (SSI®) in measuring high-precision spherical optics. Using a concave test sphere with a 25 mm radius and 36 mm aperture, the study highlights SSI’s ability to consistently measure surface form to a repeatability of just 0.007 nm RMS, with a total range of 0.025 nm. Cross-testing across different setups showed a negligible difference of only 0.09 nm RMS, validating SSI’s stability and reliability for demanding optical applications.