CASTECH Inc. engages in the research, development, production, and sale of crystal components, precision optical components, and laser devices in China and internationally. The company offers functional crystals components, including laser crystals, nonlinear optical crystals, birefringent crystals, magneto-optical crystals, acousto-optic crystals, and electro-optical crystals. It also provides precision optical components, such as windows, mirrors, spherical lenses, cylindrical lenses, aspherical lenses, non-cylindrical lenses, prisms, polarizing mirrors, waveplates, beam splitters, diffraction grating, and other special optical components. In addition, it offers magneto-optical devices, acousto-optical devices, electro-optical devices, drivers, optical switches, fiber optic transmission devices, and other products, as well as optical lenses, comprising scanning field mirrors, beam expanders, etc. Further, the company engages in the manufacturing and sale of optoelectronic components and optics crystal materials; investment in manufacturing; information transmission; software and information technology, as well as scientific research and technical services. Its products are mainly used in the manufacture of solid-state lasers and fiber lasers, and optical communications, AR, laser, radar, semiconductor equipment, optical detection equipment, industrial measurement, life sciences, precision instruments, intelligent equipment, and other fields. CASTECH Inc. was founded in 1988 and is based in Fuzhou, China.