Abstract
An optical mixture film with a low loss comprises mainly a first oxide, and a second oxide doped in a specified ratio. The mixture film with low loss is produced by an ion beam sputtering process, and treated by a high temperature annealing thermal treatment. The mixture film has a lower optical loss, i.e. a lower optical absorption and optical scattering. The mixture film can withstand a very high temperature annealing thermal treatment to reduce the optical absorption, while can maintain an amorphous state of the mixture film at a high temperature to reduce the optical scattering. Furthermore, the mixture film can be used as a film with a high refractive coefficient to be interleaved with an ordinary film with a low refractive coefficient on a glass substrate to form a reflector with a low loss.