Helga Dunken

SURFACE CHEMISTRY OF OPTICAL GLASSES

Abstract The paper presents a short survey of various surface reactions playing important roles for different treatments of optical silicate glasses. In particular, it deals with the influence of adsorbed water on the surface properties of annealed silica, chemical reactions due to glass polishing, and the ionic exchange processes between salt-melts and glasses. By means of IR-spectroscopy and contact angle measurements, it is shown that the surface tension of silica is changed by heating and that the polishing of glasses is mainly a chemical dissolution controlled by supplied mechanical energy. The ionic exchange depends on the solubility of the reaction products.

Simulation of IR and VIS-NIR spectra of Si+ implanted SiO2 glass

Abstract Si+ implanted silica glass has been investigated by IR reflectance and VIS-NIR transmittance spectroscopy. Spectra can be simulated with the complex dielectric functions of SiO2 glass and amorphous silicon by means of a simple effective medium theory and a multilayer model. It can be derived from the evaluation of the spectra that modification of the glass structure is the preferred process for ion doses