Abstract
The transient optical absorption and luminescence induced by irradiation of amorphous SiO2 with an electron pulse have been measured. It is found that the transient optical absorption spectra do not depend on impurities and have a strong peak at 5.3 eV and a satellite peak at 4.2 eV. The peak energy of the luminescence band is found to show a blue shift as the time after the pulse increases. By means of a cascade excitation experiment, the absorption band at 5.3 eV, the satellite band at 4.2 eV and the luminescence have been shown to arise from the same centre, which is ascribed to a self-trapped exciton or a metastable excited state accompanied by a large lattice distortion.