Minimizing Artifact Formation in Magnetorheological Finishing of CVD ZnS Flats

LLE Review, Volume 101 35 Introduction and Motivation The development of optics for new applications is based on the use of materials that have the appropriate mechanical and optical properties. For infrared (IR) window and dome materials that protect imaging systems against damaging conditions, three main considerations are taken into account: material strength, thermal-shock resistance, and optical characteristics, such as transmission, absorption, scattering, and emissivity. To obtain maximum transmittance, a good IR material should exhibit minimum optical scattering due to a rough surface finish. The synthetic materials that meet the requirements for IR windows could be either single crystals or polycrystalline with cubic crystallographic structure, the latter being usually tougher, which is desired.1 Polycrystalline ZnS is an excellent candidate for these applications.