High NA Concave Polishing Using Extended MRF™ Capability

Case Study Summary

QED Technologies developed an extended high numerical aperture (NA) rotational polishing mode for Magnetorheological Finishing (MRF) to enable deterministic finishing of steep concave and convex optical surfaces, including full hemispheres. This enhanced capability expands the polishing envelope of the Q-flex platform by utilizing around-the-wheel polishing to minimize B-axis travel and avoid mechanical interference, enabling geometries that were previously not polishable using standard rotational modes.

Demonstrations included concave and aspheric optics with radii near 55 mm and diameters approaching 90 mm, as well as larger diameter concave parts processed on both Q-flex 100 and Q-flex 300 systems. By leveraging multiple polishing wheel sizes from 20 mm to 150 mm, the extended mode significantly increases achievable half-angle and diameter combinations while maintaining precise surface control.

This extended MRF capability allows optical manufacturers to improve yield, reduce delivery time, and confidently process complex high-NA optics with a single modular finishing platform. The flexibility to scale capability through interchangeable polishing heads and modes positions Q-flex systems as a future-ready solution for advanced optical fabrication challenges.