The effect of oxygen on optical absorption and emission of Pr:Ga–La–S glass

The absorption and emission spectra of Ga–La–S–O glasses with fixed cation ratio Ga/La=0.7/0.3 and two oxygen contents 0.65 wt% and 2.95 wt% were studied for two Pr3+ doping levels of 0.1 and 1.0 wt%. Presence of oxygen induces blue shift of the fundamental absorption edge and results in lowering of the low-energy components of the Pr3+ absorption bands. The glasses show bright luminescence due to Pr3+ ion emission similar to that in other glasses. The effect of oxygen on the luminescence spectra is determined by the shift of the absorption edge in the short-wavelength spectra region with increasing of the oxygen contents, which became visible with oxide content growing.