US Patent 7959284 Method of making high precision optics having a wavefront profile

A method of generating a high precision optical surface profile includes obtaining a high precision optical surface profile which contains information of the optical path difference map of the profile. A substrate material has a known index of refraction, Ns, while a cover material has an index Nc that is more closely matched to the index Ns of the substrate material than the index of air Nair to Ns. An exaggerated surface profile is cut that is proportionally expanded from the high precision profile by a factor: (Ns−Nair) divided by (Ns−Nc). The cut surface profile is covered with the cover material.