Correlation between the radiation-induced intrinsic 4.8 eV optical absorption and 1.9 eV photoluminescence bands in glassy SiO2

This is the authors' abstract. We don't add key points for this paper.

The controversial relationship between the intrinsic 1.9 eV photoluminescence (the R band), the 2.0 and 4.8 eV excitation/optical absorption bands is examined for 11 specimens with different OH, Cl, and O2 concentrations and with different irradiation histories. The direct relation is found between the intensities of the R-band luminescence measured with the 4.0 eV (IUV) or resonance (1.94 eV) excitation (Ires), although it is slightly superlinear, Ires∝(IUV). The deviation from the exactly constant ratio between the band intensities in different glass samples is attributed mainly to the inhomogeneous broadening effects. Also, nonzero polarization degree, P=−1.5±0.5%, in the R-band maximum region is reconfirmed upon linearly polarized 4.8 eV excitation, substantiating a close relation between the 4.8 eV absorption band and the R band. These results suggest strongly that both of the two absorption bands at 2.0 and 4.8 eV are originated from a single center, and quantitatively agree with the recently proposed optical transition scheme in the nonbridging oxygen hole center.