Plano-concave spherical mirrors, coated with metal or dielectric film, spectral range from 250 nm to 20 µm, focal length from 9.5 mm to 500 mm. Our metal-film reflectors include UV-enhanced aluminum film (250 to 450 nm), aluminum film with protective layer (450 nm to 2 µm), silver film with protective layer (450 nm to 2 µm), gold film with protective layer (800 nm to 20 µm), and gold film with protective layer for Herriott cell (2 to 12) Including m). The average reflectivity of dielectric film mirrors is greater than 99% in the spectral range of 350 to 400 nm, 400 to 750 nm, 750 to 1100 nm, or 1280 to 1600 nm.