Chemical modification of fluoride glass surface

Ionic exchange has been carried out on vitreous fluoride materials: some fluoride ions have been replaced by hydroxyls by pyrohydrolysis of the fluoride glasses. The influence of the process parameters has been studied. The diffusion coefficients, concentration profiles and molar extinction coefficients have been calculated. An increase of the refractive index of the hydrated layers, leading to the creation of optical waveguides, has been systematically observed