CASTECH Inc. engages in the research and development, production, and sale of crystal components, precision optical components, and laser devices primarily in China. The company offers laser crystals, nonlinear optical crystals, birefringent crystals, magneto-optical crystals, acousto-optic and electro-optical crystals and other functional crystal components, and oven and temperature controller accessories; and precision optics, including windows, reflectors, spherical lenses, cylindrical lenses, aspherical lenses, mirrors, non-cylindrical lenses, prisms, polarizers, wave plates, beam splitters, diffraction gratings, and other special optical components. It also provides magneto-optical devices, acousto-optical devices, electro-optical devices, drivers, optical switches, fiber optic transmission devices, and other products, as well as optical lenses, such as scanning field mirrors, beam expanders, etc. In addition, 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.