This paper describes the preparation and properties of rf sputtered barium silicate films that are suitable for use as transmission media in integrated optical circuits. It is shown that the films, which can be produced with a wide range of refractive indices by suitable selection of the ratio of the target constituents, exhibit low optical attenuation. The techniques used to deposit the films and the effect on loss of a number of parameters including pressure, film thickness, and substrate bias are discussed.
J. E. Goell, "Barium Silicate Films for Integrated Optical Circuits," Appl. Opt. 12, 737-742 (1973)