Inrad Optics (formerly Photonic Products Group) is a company that develops, manufactures, and markets optical components, assemblies, and systems. It offers X-ray monochromators, interferometer flats, aerospace windows, metal mirrors, parabolas, and other products. Its services include optical fabrication, thin film coating, plating, CNC machining, etc. The company caters to aerospace, defense, military, and other industries.