IR Spectra Analysis of SiO_2 - TiO_2 - GeO_2 Gel Glass of CO_2 Laser Transmitting Hollow Waveguide

摘要

Roth titanium and germanium were, introduced into silicon dioxide system by sol-gel method to move its region of anomalous dispersion caused by IR resonance absorption towards the wavelength of CO_2 laser. It is indicated by IR absorption spectra that as the content of ziO_2 decreases in this glass system TiO_2 and GeO_2 tends to exist in their own phases. As for the gel glass with a composition of 40 SiO_2·30TiO_2·30GeO_2, when the temperature is below 600℃, germanium atoms exist mainly in Ce―O―Ge bonds. With the temperature increasing from 800℃ to 1000℃, titanium atoms in Si―O―Ti bonds almost transform into Ti―O―Ti bonds. Furthermore, a large number of Si―O―Ti and Si―O―Ge bonds formed when the temperature approaches 800℃, which makes a notable IR absorption band round the wavelength of CO_2 laser. Therefore, sol-gel based SiO_2 -TiO_2 - GeO_2 gel glass is a candidate material for CO_2 laser hollow waveguide.