THE INFLUENCE OF THE PSEUDO-MIXED-ALKALI EFFECT ON THE FIELD-ASSISTEDDIFFUSION OF SILVER IONS INTO GLASS FOR OPTICAL WAVE-GUIDES

Results are presented from a study of the field-assisted diffusion of silver ions from silver films into soda-lime glass. These indicate tha t it is necessary to take into consideration the concentration depende nce of the self-diffusion coefficient of both the silver and the sodiu m ions in a pseudo-mixed-alkali effect in order to predict the silver diffusion profiles accurately. A field assisted diffusion model that i ncorporates this effect is developed and model coefficients are deduce d. The model is applied to post-bake diffusions and deep field-assiste d diffusion profiles. The model is applicable to the design and manufa cture of optical waveguides and lenses in glass by field-assisted diff usion.