Extending Magnetorheological Finishing to Address Short Radius Concave Surfaces and Mid-Spatial Frequency Errors

Case Study Summary

This case study highlights how QED Technologies expanded the capabilities of Magnetorheological Finishing (MRF®) using a smaller, 10 mm wheel to polish optics with short-radius concave surfaces and to correct mid-spatial frequency (MSF) errors. The study demonstrated successful polishing of a 7.8 mm radius optic on the Q-flex 100 platform with 83% convergence and only 14.5 nm RMS of removal error.

Additionally, the smaller wheel size improved correction efficiency for MSF features smaller than 1 mm—achieving a reduction from 7.9 nm RMS to 2.8 nm in a single pass. These results show the effectiveness of MRF in achieving nanometer-level precision and enhanced feature correction for high-NA parts, reference surfaces, and advanced optical applications.