Quantitative analysis of the concentration of interstitial O2 molecules in SiO2 glass using luminescence and Raman spectrometry

Abstract

The Raman band of the stretching vibration of interstitial oxygen molecules in glassy SiO2 is found at 1548.5±1 cm−1. By comparison with the Raman spectrum of gaseous O2 (Q band at 1555.5 cm−1), the concentration of the interstitial O2 molecules in Suprasil W1 synthetic fused silica is estimated as (8±3.5)×1017 (molecules O2)/cm3. This value is further used to calibrate the intensity of the Nd-YAG laser-excited O2 a→X infrared photoluminescence band at 1272.2 nm against the intensity of the fundamental Raman bands of glassy SiO2. In this way, quantitative measurements of O2 concentrations in SiO2 down to at least ≈1016 molecules/cm3 are possible.