Magnetorheological method applied to optics polishing: A review

Magnetorheological finishing method is carried out in order to correct errors of figures which are produced by conventional polishing methods on planes, spheres, aspheres and freeform optics having surface roughness value as low as 1 nm RMS. Low surface roughness and mid-spatial frequencies in advanced optical systems are essential for minimizing flare and energy loss. Magnetorheological polishing fluid is a clever fluid that can alternate from its liquid phase to almost solid under magnetic field influence. The main key process parameters in magnetorheological finishing process such as fluid composition, rheological properties along with the surface quality of polished optical components (including metal, glass, and ceramic) are reviewed in the present manuscript.