Process for Producing High-Quality, Lightweight Mirrors

Virtually all conventional lightweight mirrors are made by optically grinding and polishing an already lightweighted blank. Mirrors made this way always risk print-through to the optical surface. In some cases, this can be removed by a zero-pressure process, such as ion-beam polishing, although these processes tend to be slow and costly. Lightweighting after optical polishing is not an option for conventional materials as their inhomogeneous qualities and internal stresses cause the lightweighting to distort the optical surface.