Correlation between Ge E Centers and Optical Absorption Bands in SiO2:GeO2 Glasses

Abstract
Correlations between optical absorptions in ultraviolet and vacuum ultraviolet regions and Ge E centers were examined using 9SiO2·1GeO2 glasses irradiated with ArF excimer laser light in order to determine the optical absorption bands due to Ge E centers and the oscillator strength. A good correlation between the band peaking at 6.3 eV and Ge E centers was found in the isochronal annealing experiment. The oscillator strength of the 6.3 eV band was determined to be 0.5±0.1 on the assumption of the above correlation. The large oscillator strength of the 6.3 eV band due to Ge E centers is compatible with the Kramers-Kronig mechanism for photoinduced Bragg grating formation.