Dispersion measurements of optical waveguides

Dispersion curves are reported for optical waveguides formed by ion implantation or ion exchange. All ions implanted into silica are found to produce an increase in refractive index of about 1% over the range 0.42-0.63 mu m. Ion exchange guides have been fabricated by thermal diffusion of ions in soda-lime glass, and show an increase in index of about 4% over the same range. The experimental arrangements are described for mode-angle and attenuation measurements using prism couplers. The difference in the theory between buried and surface guides is indicated and the modification used to calculate the index changes for implanted and diffused guides respectively.