Effect of ion implantation on the refractive index of glass

Studies on the changes of the index of refraction in glass due to ion implantation provide an insight into the structure of amorphous substances, besides being important for the development of techniques for the production of optical integrated circuits. Using a heavy ion accelerator, optically flat samples of Pyrex and Corning borosilicate glass were implanted with ions of gallium and argon at various incident energies and doses. The refractive index was then measured and found to be between 1.5 and 1.8 at a wavelength of 5893 A.U. The change in the refractive index was found to vary linearly with the incident dose irrespective of the ion species. This suggests that bombardment damage is mainly responsible for the effect. The dependence of the refractive index change on the incident dose however depends strongly on the chemical composition of the substrate glass.