Raman spectrum and refractive index behavior of Al2O3added highhyphen;silicahyphen;content glass

摘要

Several specimens of Al2O3hyphen;added highhyphen;silicahyphen;content glass of various additive concentration which were prepared with a chemical vapor deposition (CVD) process are studied by Raman spectroscopy. The Raman spectrum of the glass is found to be close to that of fused silica, and the Raman band characteristic to the nonbridging oxygens was not observed in this glass. A quadratic behavior of the refractive index change as a function of the additive concentration is observed in this glass and is explained with a detailed ionic polarizability concept on the basis of the Raman spectroscopy. The effect of the refractive index fluctuation in this glass on the optical attenuation is also discussed.