Lightweight Metallic Mirrors

Imaging systems for space and airborne platforms have aggressive Size, Weight and Power (SWaP) requirements. High quality, lightweight optics help enable these types of systems. Today typical light weighting techniques are accomplished through removal of material in the back structure with classical machining and the use of low-density, high-stiffness materials such as beryllium. We present a novel methodology for generating lightweight metallic mirrors that are fabricated by growing an additive manufactured blank, fly cutting the surfaces to be mirrored, and post processing the faces by coating them with electroless nickel and then diamond turning. This process was used in a case study for the development of a topology optimized, low-weight and high-stiffness spinning mirror. The mirror was fabricated with selective laser melting and post processed to deliver optical quality mirror surfaces.