Buried optical waveguides in fused silica by high−energy oxygen ion implantation

Oxygen ion implantations in fused silica in the energy range 0.3−2 MeV with doses ranging from 1014 to 1016 ions/cm2 are conducted at room temperature. The optical parameters of the guides obtained are measured before and after successive annealings with the help of a prism−film coupler. Also, an investigation of the buried nature of these guides is carrier out by conducting the above measurements before and after removing a known thickness of the implanted layer by argon plasma etching. It is reported that the contribution to refractive index increase in the surface region due to ionization effects cannot be ignored during the realization of buried guides by high−energy ion implantation. Also, it is shown that these guides get buried depending on the annealing treatment.