Meller Optics, Inc. custom manufactures sapphire lenses for aerospace applications such as the field flattener focusing lenses used in CCD arrays on the Kepler Space Telescope.
Meller Sapphire Lenses are custom manufactured with surface finishes from 60-40 to 40-20 scratch-dig, flatness held to 0.5 fringes of HeNe, and parallelism from 20 to 2 arc/secs., depending upon configuration. Selected by NASA for use in the CCD arrays on the Kepler Space Telescope, these sapphire field flattener focusing lenses withstand extreme conditions.
Impervious to water, most acids, alkalis, abrasion from fast-moving particulates, temperatures to 1,000°C, and pressures up to 10,000 psi, Meller Sapphire Lenses can be manufactured in sizes from 3/8" to 4" dia. and varying wall thicknesses with ±0.001" tolerances in plano-convex, -concave, meniscus, and dome configurations. Edges can be beveled and polished.