Even though the only polishing mode our Q22-X machine has is rotational, we do have obtained positive results in figure-correcting ZnSe prism with MRF. A special jig is designed and machined to mount the prism so that the surface to be polished is aligned perpendicularly to the axis of the spindle. Since the ZnSe material is very soft, special cautions have been taken to polish the part will a very mild spot so the surface being polished will not be damaged - it is found that the "orange-peel" effect will be observed on the surface if aggressive MRF polishing is carried out on the surface. In the end, a surface flatness of better than 1/5 waves has been routinely obtained.
On the other hand, a surface irregularity of better than 1/20 waves has been routinely obtained if prisms of optical glass or fused silica is figure-corrected on the MRF machine.