A 1.9 eV photoluminescence induced by 4 eV photons in high-purity wet synthetic silica

Photoluminescence (PL) of type III (high-purity wet synthetic) silica excited by a XeCl excimer laser (hν=4 eV) is reported. Time-resolved spectra show that a PL band peaked at 1.9 eV can be induced by the XeCl laser irradiation. This band exhibits a fast rise time (<20 ns) but a decay time of several microseconds. The possible mechanisms of photogeneration and photoexcitation of the defects related to this emission are discussed.